[arrandale] desktop is messed up with external monitors (x86_64)

[Roland Dreier]

Binary package hint: unity

(I'm not sure where in the stack this problem really is, so I'm guessing and picking on unity)

I have a Lenovo T410s laptop with Intel graphics and I use it with a dock with two 1920x1200 monitors connected. I'm running up-to-date Natty. If I boot the laptop with it already docked, everything works perfectly: the two external monitors are used and I get a nice unity desktop spanning my 3840x1200 space.

However, if I boot with the laptop undocked, log in, and then dock the laptop, it breaks pretty badly. Only one monitor is lit up, and I just get a black screen with a mouse pointer there -- no desktop background, windows, toolbars, or anything. Once it's in this state, it doesn't seem possible to recover -- if I undock the laptop again, the internal screen just stays black with a pointer.

When the laptop is in a working state, undocking it sort of works... the desktop switches to the laptop screen, but then redocking it acts just like docking as described above.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: unity 3.6.8-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic x86_64
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,scale,session,unityshell]
CompositorRunning: compiz
DRM.card0.DP.1:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
DRM.card0.DP.2:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
DRM.card0.DP.3:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
DRM.card0.HDMI.A.1:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
DRM.card0.HDMI.A.2:
 status: connected
 enabled: enabled
 dpms: On
 modes: 1920x1200 1920x1080 1920x1080 1600x1200 1680x1050 1400x1050 1280x1024 1280x1024 1440x900 1360x768 1152x864 1280x720 1280x720 1024x768 1024x768 1024x768 832x624 800x600 800x600 800x600 800x600 720x576 720x480 640x480 640x480 640x480 640x480 720x400
 edid-base64: AP///////wA4o1BnAQEBASUUAQOAOCN46pe1qVQ4riUTUFS/74CBwIGAkECLwJUAqUCzANEAKDyAoHCwI0AwIDYAMF4hAAAaAAAA/QAyTBpSEQAKICAgICAgAAAA/ABFQTI2MVdNCiAgICAgAAAA/wAwOTEwNjY4OE5BCiAgAV4CAQQAAR0AclHQHiBuKFUAMF4hAAAeAR0AvFLQHiC4KFVAMF4hAAAejgrQiiDgLRAQPpYAMF4hAAAYjArQkCBAMSAMQFUAMF4hAAAYAjqAGHE4LUBYLEUAMF4hAAAeAjqA0HI4LUAQLEWAMF4hAAAeAAAAAAAAAAAAAAAAAAAA/A==
DRM.card0.HDMI.A.3:
 status: connected
 enabled: enabled
 dpms: On
 modes: 1920x1200 1920x1080 1920x1080 1600x1200 1680x1050 1400x1050 1280x1024 1280x1024 1440x900 1360x768 1152x864 1280x720 1280x720 1024x768 1024x768 1024x768 832x624 800x600 800x600 800x600 800x600 720x576 720x480 640x480 640x480 640x480 640x480 720x400
 edid-base64: AP///////wA4o1BnAQEBASUUAQOAOCN46pe1qVQ4riUTUFS/74CBwIGAkECLwJUAqUCzANEAKDyAoHCwI0AwIDYAMF4hAAAaAAAA/QAyTBpSEQAKICAgICAgAAAA/ABFQTI2MVdNCiAgICAgAAAA/wAwOTEwNjY5ME5BCiAgAWUCAQQAAR0AclHQHiBuKFUAMF4hAAAeAR0AvFLQHiC4KFVAMF4hAAAejgrQiiDgLRAQPpYAMF4hAAAYjArQkCBAMSAMQFUAMF4hAAAYAjqAGHE4LUBYLEUAMF4hAAAeAjqA0HI4LUAQLEWAMF4hAAAeAAAAAAAAAAAAAAAAAAAA/A==
DRM.card0.LVDS.1:
 status: connected
 enabled: enabled
 dpms: Off
 modes: 1440x900 1440x900
 edid-base64: AP///////wAwrjZAAAAAAAASAQOAHhN46uWVk1ZPkCgoUFQAAAABAQEBAQEBAQEBAQEBAQEBwSmg5FGEGjAwIDYAL74QAAAZ3iKgLFGEfjAwIDYAL74QAAAZAAAADwCVCjKVCigeCQBMo0JUAAAA/gBMVE4xNDFCVDA4MDAxAMs=
DRM.card0.VGA.1:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
Date: Tue Mar 29 10:07:56 2011
DistUpgraded: Log time: 2010-12-12 14:04:29.713775
DistroCodename: natty
DistroVariant: ubuntu
EcryptfsInUse: Yes
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21c1]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20101206)
InstallationMedia_: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20101206)
InstallationMedia__: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20101206)
MachineType: LENOVO 2901CTO
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic root=UUID=ab1e5491-e40c-4113-bf20-22ecb604999a ro quiet splash vt.handoff=7
ProcVersionSignature_: Ubuntu 2.6.38-7.39-generic 2.6.38
ProcVersionSignature__: Ubuntu 2.6.38-7.39-generic 2.6.38
Renderer: Unknown
SourcePackage: unity
UpgradeStatus: Upgraded to natty on 2011-03-24 (4 days ago)
dmi.bios.date: 10/27/2010
dmi.bios.vendor: LENOVO
dmi.bios.version: 6UET61WW (1.41 )
dmi.board.name: 2901CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6UET61WW(1.41):bd10/27/2010:svnLENOVO:pn2901CTO:pvrThinkPadT410s:rvnLENOVO:rn2901CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2901CTO
dmi.product.version: ThinkPad T410s
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.4git20110322-0ubuntu5
version.libdrm2: libdrm2 2.4.23-1ubuntu5
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.1-0ubuntu3
version.xserver-xorg: xserver-xorg 1:7.6~3ubuntu11
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu6

[lspci]
Nux: lspci: 00:02.0 VGA compatible controller [0300]: Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02)

[Alex Launi (alexlauni)]

The issue you're describing doesn't sound related to Unity. Could you log into a Gnome 2 session and see if this issue persists?

[Roland Dreier (roland.dreier)]

Yes, I get similar issues when logging into a "classic" session and in fact when the system is at the gdm screen before logging in. So I reassigned to the intel driver, since this appears to be a generic X problem.

[Bryce Harrington (bryce)]

Actually is most likely an issue in the kernel's drm modesetting code.

[Bryce Harrington (bryce)]

I think this is probably a dupe of bug #737891.

[Bryce Harrington (bryce)]

Can you try temporarily uninstalling ia32-libs and reproducing the issue, to rule out that as a possible suspect? (We had a bug on arrandale x86_64 recently that we believe was due to an old mesa in ia32-libs, but that should be fixed now.)

[Roland Dreier (roland.dreier)]

OK, with ia32-libs uninstalled:

   $ dpkg --list|grep ia32
  rc ia32-libs 20090808ubuntu11 ia32 shared libraries for use on amd64 and ia64 systems

I get roughly the same behavior. I started with the laptop docked, and when I undocked it actually switched to the internal screen OK. Then when I redocked I got the black screen, and when undocking again I was stuck with the black screen too (only showing a pointer that still moves with the mouse).

[Bryce Harrington (bryce)]

Hrm, ok at least it rules out ia32-libs.

Next thing to look at is the GPU registers. Please install xserver-xorg-video-intel-dbg and run the tool intel_reg_dumper once when the screen is working correctly, and once with it showing the blank screen / out-of-range error, and attach both files. Comparing the register settings for them may highlight where the problem is.

[Hannes Beyer (hannesbeyer)]

I'm observing the same problem here. I also have a Lenovo T410s. When booting with the dock connected to a 19" monitor (1280x1024, DVI) both monitors turn black on ubuntu 11.04 beta 2 after login. LVDS1 stays black upon undocking but the mouse cursor is visible. The login screen is there, but here the resolution is not set properly.
When booting undocked and connecting the unit to its dock at a later timepoint, monitors also turn black.
Connecting a 1900x1080 TV via displayport to the notebook -without the dock- woked for me.
Things worked fine with ubuntu 10.10.

[Roland Dreier (roland.dreier)]

OK, I got a chance to run intel_reg_dumper when the system is in the following states:

 - docked-good.txt : in the dock with unity working properly spanning two external 1920x1080 monitors
 - docked-bad.txt: in the dock with a black screen on the left monitor and the right monitor off
 - undocked-good.txt: out of the dock with unity working properly on the internal 1440x900 LCD
 - undocked-bad.txt: out of the dock with a black screen

[Roland Dreier (roland.dreier)]

correction: I said two 1920x1080 monitors but they are really 1920x1200 monitors.

[Bryce Harrington (bryce)]

Roland, thanks for that.

Alright, here is what I think is happening. Arrandale graphics cards have a hardware limitation of a max texture buffer size of 4096x4096. What this means is that compositing will work only if the total screen width is 4096 or less. Over that, and the GPU can lock up or other weird things can occur.

My hypothesis is that when you are booting with the laptop docked, the internal laptop LVDS panel is disabled, so your total width is 1920+1920 which is <4096. However, when you boot with the laptop panel on and *then* dock, the kernel is adding the two monitors to the left or right of the laptop panel, resulting in 1920+1920+1440 which is >4096.

Looking at your monitors.xml, the first section shows HDMI2 and HDMI3 arranged side-by-side, and LVDS1 is also present and not disabled but not set to any particular position, so it is unclear how the kernel would position it in this case; perhaps it is adding it at +3840+0 which would fit with my hypothesis.

There are a few things you could test which might prove my hypothesis wrong:

a. This behavior should occur only with Unity/Compiz. If you boot Classic Desktop (No Effects), the system freeze should be unreproducible. (However, see below)

b. If in gnome-display-properties you arrange your LVDS to be positioned *below* your two main monitors, it should work in unity. Note you may need to delete your monitors.xml before making these settings.

c. If you disable your LVDS before docking (either using the GUI, or via 'xrandr --output LVDS1 --off') and then docking, the system shouldn't freeze. (I don't know if the external monitors will fire up in this case, but at least it won't trigger the freeze bug).

These may also give you some idea on working around the issue.

If those tests turn out correct, then this issue is basically a sub-case of bug #555641. However, I think that there could be some work done in gnome-display-properties to check max texture size before enabling configurations like this, if compiz is running.

Now, one other caveat. It appears that there is a separate unrelated bug that is common to Arrandale, that certain RANDR operations can sometimes result in a monitor being improperly blanked. So, that may add some confusion to your testing. But the way to tell these bugs apart is that your original bug results in a system lockup (a black screen with a mouse pointer, and no way to recover), whereas with this latter blanking bug, you won't see a mouse cursor and the monitor will appear to be not getting any signal. Possibly you may be able to work around this blanking issue via this command:

xset dpms force on

Anyway, sorry for the lengthy dissertation, but hopefully with this information you can help me nail down this bug. I have some thoughts on what steps to take to get resolution to this issue (and the blanking one) but let's see if you can prove my hypothesis before we get into all that.

[Roland Dreier (roland.dreier)]

Bruce, thanks for all the info. I will do some more testing today.

One clarification though: when I get in the black screen + mouse pointer situation, my machine is not hung. In fact the mouse pointer is still responsive, I can log in via network, etc. It just that I lose the X root background, WM stuff, etc.

Also I believe I did see similar problems with classic, although I need to double check the "no effects" part. I definitely have seen it from the GDM screen.

[Roland Dreier (roland.dreier)]

Bryce, first off, sorry for mistyping your name ;)

I did a bit more testing, and I tried the classic/no effects login again. If I start undocked and dock, I do get the black screen/responsive mouse pointer. However, if I log in with classic/no effects *and* do "xrandr --output LVDS1 --off" and then dock, one monitor lights up with a real desktop (ie it seems to work). The second monitor was off, but I was able to get it to light back up by going to a text console and back to X. (I guess this is the second conflating bug you mentioned).

I tried a standard unity login and did the "xrandr --output LVDS1 --off" and I still ended up with a black but on monitor.

[Bryce Harrington (bryce)]

Hi Roland, thanks for the quick response.

Regarding your clarification, yes despite how it may seem, "blank screen with moving mouse cursor and X not responding to input, but network login works" is the prototypical set of symptoms that go with a GPU hang. The kernel itself is ok, which is why you can ssh in; the mouse cursor is handled far enough outside the core of X that it is often unaffected by lockups (not always though). Often when you have a GPU lockup, there will be an error message in your 'dmesg' output. The file /sys/kernel/debug/dri/0/i915_error_state often displays error codes when the GPU is locked up. In fact, if you could reproduce the bug with the classic/no-effects case and attach both of those here, it might give us some more clue what's going wrong. Or, at least, it gives me plenty of info to take upstream.

Regarding the second conflating bug (which I suspect might be a DPMS bug in the kernel's arrandale code), I've a PPA you could try to see if it at least improves that situation:

  https://launchpad.net/~bryce/+archive/elderberry

[Roland Dreier (roland.dreier)]

I added that ppa and updated, and did a bit more testing. It seemed to work a bit better, though not in the way I would have expected.

classic/no-effects: I started undocked, and actually got docking once to work perfectly (both monitors lit up, desktop displayed on both). However when I undocked and re-docked again, my right monitor didn't light up (although I got my desktop on the left monitor). I was not able to get the right monitor to turn on again, after trying "xset dpms force on" , the gnome monitor GUI, going to tty1 and back, etc. This situation was stable after a couple more undock/redock cycles. I never got into the black screen/moving mouse pointer situation. The kernel log never showed any intel graphics related stuff (just USB devices appearing/disappearing and other docking related stuff). And i915_error_state stayed "no error state collected".

unity: Again I actually got docking to work once; however the second time I docked, I got the black screen/moving mouse pointer and right monitor stuck with no signal. However neither the kernel log nor the error_state file showed anything.

[Roland Dreier (roland.dreier)]

I just noticed something while looking at my Xorg.0.log after a couple of dock/undock cycles leading to the black screen. I'm attaching the full log, but what I noticed was:

boot up undocked:
[ 5.897] (II) intel(0): Allocated new frame buffer 1472x900 stride 6144, tiled
matches a 1440x900 panel

dock:
[ 370.652] (II) intel(0): Allocated new frame buffer 3840x1200 stride 15360, tiled
makes sense, I now have 2x1920x1200 monitors

undock:
[ 414.405] (II) intel(0): Allocated new frame buffer 1472x900 stride 6144, tiled
back to the 1440x900 panel

dock again:
[ 434.873] (II) intel(0): Allocated new frame buffer 1920x1200 stride 7680, tiled
now it only allocates a buffer for one monitor -- which probably explains why the second monitor never lights up

I'm not sure what layer of the stack is responsible for figuring out what buffer to allocate etc but this does seem like the first real clue I've seen to where the problem lies.

[Bryce Harrington (bryce)]

Hi Roland, that's a good eye. It is the kernel modesetting portion of the stack which allocates framebuffers, and that does tend to indicate where in the core logic things may be going awry.

Since you're results with the elderberry PPA sound mixed, it's sounding to me like it would not be worth pursuing getting that change into natty. Do you agree, or do you see some value to it?

[Roland Dreier (roland.dreier)]

I don't think the elderberry stuff is related to my issue -- I see a monitor stuck with no signal because (if I understood correctly) KMS got confused and forgot about it. Probably fixing KMS would fix my problems.

Is there some i915 tracing I could turn on to figure out what is confusing the kernel driver?
I guess I'll try a 2.6.39-rc upstream kernel to see if that makes any difference.

[Bryce Harrington (bryce)]

On Thu, Apr 21, 2011 at 12:27:20AM -0000, Roland Dreier wrote:
> I don't think the elderberry stuff is related to my issue -- I see a
> monitor stuck with no signal because (if I understood correctly) KMS got
> confused and forgot about it. Probably fixing KMS would fix my
> problems.
>
> Is there some i915 tracing I could turn on to figure out what is confusing the kernel driver?
> I guess I'll try a 2.6.39-rc upstream kernel to see if that makes any difference.

Yes, the xdiagnose utility allows switching on drm debug messages (the
first checkbox). You might also experiment with disabling vesafb but
I'm doubtful that would do anything in this case.

In addition to testing the .39-rc kernel, you can test Intel's
experimental tree which we package for Ubuntu now for testers:

http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next-proposed/

[Roland Dreier (roland.dreier)]

With linux-image-2.6.39-999-generic_2.6.39-999.201104201108_amd64.deb docking/undocking seems to work pretty well. There is a bit of a delay in switching, but even through a few cycles with unity running, I was able to switch successfully between the internal LCD and the two external monitors.

I captured some kernel logs, and when I get a chance I'll do the same for the stock natty kernel so we can compare.

[Bryce Harrington (bryce)]

I have duped bugs #750259, #734756, and #747205 here.

Bug #737891 also exhibits this same issue but also conflates it with another issue where creating a screen >4096 wide exceeds the max texture width (as per the linked upstream bug), so I'm going to let that bug focus on that particular issue (which really is more of a gnome configuration tool issue).

[Bryce Harrington (bryce)]

On lp #747205 we discovered by creating a new user account, that having certain RANDR operations present in monitors.xml would trigger it, presumably because gnome-settings-daemon would pick up those configuration settings and try applying them, triggering an underlying bug in RANDR. Perhaps fiddling with the primary monitor setting did it?

734756 collected register dumps on the issue, and experimented with some dpms forcing from the userspace side. My elderberry PPA was found to have some positive effects, but didn't fix it sufficiently completely to warrant pursuing that to work around the kernel issue. drm-intel-next-proposed did not boot on this reporter's hardware.

Video and photos are available on bug #750259. We also examined gpu error states and found this bug is not a gpu lockup issue (as 747205 suggested). The drm-intel-next-proposed kernel from around 4/21 was found to fix it.

Bug #737891 includes reports of this issue, among other problems. Maverick was re-tested via livecd and the issue was not reproduced (maybe for the same reasons as creating a new account in bug 747205 did not reproduce? Reporters also found that deleting monitors.xml has an ameliorative effect.) Fiddling with which monitor was listed as primary in monitors.xml appeared also to resolve things for at least one person.

[Bryce Harrington (bryce)]

Bug #761236 is the broken-out portion of bug #737891 which is this specific issue. On that report, it was found that kernel 2.6.39-0.4~20110419 resolved it, but the elderberry PPA with the -intel workaround did not.

[Bryce Harrington (bryce)]

That should capture all the background on the various instances of this bug that I've been working with people on. Basically, there are some variations in symptoms but all of the reports are particular to Arrandale, occur in relationship with setting up external screens (perhaps something relating to primary monitor settings), and appear to be fixed in the latest kernel.

The next step for this bug is that we need to narrow down what patch in the upstream kernel provides the fix. The best way to achieve this is via doing a git bisection search. Unfortunately none of us Ubuntu-X guys have Arrandale hardware, so if this bug is going to get fixed in natty we need a volunteer to do this. It is a bit technical but well documented in a paint-by-numbers fashion at https://wiki.ubuntu.com/Kernel/KernelBisection.

[Bryce Harrington (bryce)]

An alternative thing to investigate: There is another bug particular to Sandybridge, with roughly similar symptoms to this one, which has already been git bisected and found a candidate patch. The flagged patch with the fix appears to also affect Arrandale, so I have a hunch it *might* also solve this bug. But that's just a wild guess. Please install and boot this kernel to see if the issue can be reproduced; if not, then this bug may be a dupe of bug #761065:

http://people.canonical.com/~acelan/bugs/lp753189/

[Greg Wilkins (gregw-wiltel)]

I was having a very similar issue with a thinkpad X201 (see https://bugs.launchpad.net/bugs/771344 - which is now duped here)

However, booting with the monitors plugged in made no difference - I would go to the black screen regardless when I logged in an existing account.

However, a freshly created account was able to display two monitors and worked OK with monitor connects and disconnects.

I removed all the compiz files from the existing account and then logged in with a classic no affects session. This gave me black screens, but I was able to hit fn-f7 and my screens cycled through various combinations. Some of these were all black, but some worked, including both screens full resolution (not mirrored) and just external monitor.

I was then able to log out and back in with a classic with effects session, and this now works! However, if I fn-f7 too much, then eventually I end up in the black screens with only X cursor situation and have to restart X to get out of it.

[Unkraut (unkraut2)]

Dear Bruce!

I tried your kernel and experienced exactly the same problems as with the stock ubuntu kernel.
Could anyone please confirm this?

[Unkraut (unkraut2)]

Switch back to kernel 2.6.35-28 from maverick solved most issues for me. I can recomend this as a workaround.

[Hannes Beyer (hannesbeyer)]

I installed kernel 2.6.36-020636.201010210905_amd64 what also wokrd for me. I can conveniently switch between internal and external monitors. Docking/Undocking and weaking up from suspend works which is a pain with the 38er kernel.

[Ed Swierk (eswierk)]

I installed kernel 2.6.39-994.201104200727 from http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next-proposed/. This solves the blank screen issue when an external monitor is connected (ThinkPad T410s with Natty).

[Sebastián García Rojas (sebagr)]

I've just installed linux-headers-2.6.39-020639rc4 and this fixed the problem for me!

[Peter L. Hansen (peter-r12)]

I installed kernel 2.6.39 and it too fixed the problem on my ThinkPad T410 such i can use it with my docks again, with different configurations.

But the machine has been significantly slower and it has introduced crashes. Is this because of the PPA software? Debug mode or something the like?

[Martin Pool (mbp)]

Is it worth updating the title to clarify this bug also apparently covers cases where just a single monitor doesn't work (as some of the bugs duped to this complain.)

[Bryce Harrington (bryce)]

[I've marked this bug for inclusion in our oneiric bug queue. While technically this bug has not been re-confirmed against oneiric, I feel it is worth continued development attention. We will need to ask that it be re-confirmed once oneiric is further along, perhaps once we get closer to alpha.]

[Ruairi (ruhann)]

I installed 2.6.29 from the PPA, this fixed the problem in ubuntu classic. In the unity desktop with 2.6.39 I can have choose one monitor only, with two monitors I have issues where the workspace is not the same size as the screen.?field.comment=On a Lenovo Thinkpad Edge, installing 2.6.39 from the Kernel PPA also fixes the problem in ubuntu classic. In the unity desktop with 2.6.39 I can have choose one monitor only, with two monitors I have issues where the workspace is not the same size as the screen. (See attachments). A workaround can be made by setting up the screens in classic mode and the logging out and logging into the unity desktop (see last attachment)?field.comment=On a Lenovo Thinkpad Edge, installing 2.6.39 from the Kernel PPA also fixes the problem in ubuntu classic. In the unity desktop with 2.6.39 I can have choose one monitor only, with two monitors I have issues where the workspace is not the same size as the screen. (See attachments). A workaround can be made by setting up the screens in classic mode and the logging out and logging into the unity desktop (see last attachment)

[Yoni Tsafir (yonix85+launchpad)]

Had a similar bug on my ThinkPad x201.

Installing 2.6.39 kernel as suggested solved the frequent crashes, but certain areas of the screen still remained unusable.
Finally, the workaround I found for this was to delete ~/.config/monitors.xml

[jeffbl (jeff-mulb)]

I also had to delete my monitors.xml on my thinkpad x201. I've also found that putting one display above the other is a recipe for disaster - Chrome especially freaks out and makes a short window that can't be expanded, rendering it useless, and all my windows lose their titlebars routinely. Putting my displays side-by-side has far fewer problems. I suspect that I triggered this bug by fiddling with my monitors one on top of the other. I haven't gotten it into a bad state with the monitors side-by-side.

[sirovsky (david-sirovsky)]

I have a similar issue on my Thinkpad Edge 14 (Natty 32bit), when working in the Classic session.

Upon plugging in an external monitor [via HDMI], (or when booting with it plugged, after entering the session), the screen goes black (no mouse pointer either), with the external monitor picking no signal.

When unplugging, the laptop has a non-functional black screen with a mouse pointer.

The fix from [https://launchpad.net/~bryce/+archive/elderberry] did not help.

[My symptoms match more closely those in duped #749817].

[Obi1Kenobi (hatespam00-bugrep)]

Intel D820 here with Intel Mobile GM965/GL960 Integrated Graphics Controller. I use a docking station with two identical HP LA1951g monitors attached, one VGA, one DVI with a native resolution of 1280 x 1024 @ 60 Hz.

First, Natty failed to detect the native resolution of VGA monitor. It can only see 1024 x 768 (all effects were off). Maverick had no problems with seeing 1280 x 1024 (though have used a xorg.conf file).

Even when docked and with the lid shut, the laptop still displays on the LVDS only (?!?) - and with a weird resolution too. Attempts to shut off the LVDS and force image on the external display leads to black screen on all three of them followed by a system freeze (CTRL+ALT+POWER is the only way to reboot it).

Had no such problems whatsoever with Maverick so it must be a Natty bug. Have tried the xorg-edgers drivers and used the same xorg.conf file from Maverick to no avail.

Since in its current status Natty is completely unusable, I had to put Maverick back (which I am using to write this post).

Another thing: is it just me or the fonts did look a lot smoother and clearer in Maverick than Natty ?

[Obi1Kenobi (hatespam00-bugrep)]

Errata: on my previous post "Intel D820" should read "Dell 820". My apologies.

[sirovsky (david-sirovsky)]

Follow up on my previous post (#42) .

Thinkpad Edge 14:

kernel 2.6.39-rc4 (x86) has fixed the issue.

[Neil Crighton (neilcrighton)]

I also had this problem with an x201s. The display on the laptop alone was fine, but on attempting to plug in an external display, both displays go black. I downgraded my linux kernel from 2.6.38-9 to 2.6.35-22-generic from the maverick repositories and this seems to have fixed the problem.

[entonjackson (aj-mysc)]

In Natty 32bit with Unity when I plug in a beamer, the beamer is recognized, and you can see the panel at the top, but not the wallpaper, so the rest is black. Putting windows via drag and drop to the beamers side makes me see the grabbing hand cursor, but not the window itself. Changing Resolution on each screen makes no difference.
Making a reboot, or having the beamer plugged in on booting up makes it work, like it did in 10.10

I have Dell Vostro 1520 with an intel video card and the current drivers installed.
Anybody has a solution?

[Bryce Harrington (bryce)]

To re-emphasize what I said in comment #28:

The next step for this bug is that we need to narrow down what patch in the upstream kernel provides the fix. The best way to achieve this is via doing a git bisection search. See https://wiki.ubuntu.com/Kernel/KernelBisection.

From the comments it sounds like three things are needed:

  * The mainline kernel .39
  * Delete your .config/monitors.xml
  * Don't arrange monitors one above the other (interesting; why? maybe unrelated bug?)

None of us X devs have arrandale HW, so progress on this bug is blocked until someone who *does* have it can do the git bisection work to narrow the patches. I asked Intel about this bug today but they didn't know offhand what patch(es) should be pulled either.

[Adam Thompson (athompso)]

@Bryce: According to that page,
    Required knowledge and tools
    The rest of this page assumes that you know how to fetch a kernel from the Ubuntu git repository, and build it, and that you have basic git skills. If you can't do that yet, try starting with this wiki page.

So there's the fundamental stumbling block for most users. I can probably figure it out, given a bit of time, although I haven't had to go bug-hunting in the kernel since 0.9-something.

Also, I do not know of a working kernel version that I can use to narrow it down. This laptop has only ever run 11.04, so far... I have no idea what effect downgrading to 2.6.35-22 will have on this system.

And, of course, I really have no great galloping desire to burn a day or two doing kernel rebuilds. But someone has to, eventually, to get this fixed - might as well be me :-(

It would probably be easier to ship a cheap Arrandale laptop with DP-out to one of the X devs... *sigh*

[wahlau (wahlau)]

I have been bothered by this flickering and automatic display switching issue since installation of Natty (also previously when i upgraded from Maverick to Natty). I am glad to find this bug here, and tried some of the proposed solutions (mainline, backport to maverick). None of them really works for me.

My setup is as follows: I have a T410s running natty fresh installed. At office i have an old dell Fp2001 and a mini dock 3, at home a Samsung 225BW without dock. I realise with the office setting i do not seemed to have the issue at all, but only at home i experience the switching(flickering) and crash if i attempt to FN-F7 for a few times.

Now the only setup that somehow works is - maverick kernel 2.6.35-02063513-generic from mainline kernel, and with compiz turned off then the system somehow works. When i have time i will try the 2.6.35-22 (which should be the 2.6.35-4 in mainline i suppose?) and see if that helps me.

My suspicion is: the kernel attempt to detect the connected external monitor, but due to some unknown reasons, it made the decision that the monitor is missing (due to weak signal via the cable or refresh rate?) therefore attempt to automatically change back to internal display. And if only external monitor is selected, then the flickering mode is selected.

hope my report and experience here helps a little. I have no idea about the bisection thing - if it is not too difficult or time consuming i am willing to help perhaps next week.

thanks.

regards, wahlau

[René Vangsgaard (rene-vangsgaard)]

Thinkpad X201s worked perfectly on 10.10, but is broken on 11.04. Every time I dock/undock, plug/umplug monitor or projector, screen goes blank. I can switch to a virtual terminal; sometimes I can restart GDM successfully, sometimes I have to do a reboot.

[pbburns (pbburns)]

Thinkpad x60s. Broken after upgrading to 11.04. Almost always when I switch to external monitor most of the screen is black. Sometimes the entire screen is black except for the top bar. Very occasionally I can switch to the external monitor fine (< 10% of the time).

[Martin Pool (mbp)]

I will try the bisection.

[Martin Pool (mbp)]

I tested with Oneiric's kernel http://packages.ubuntu.com/oneiric/linux-image-2.6.39-3-generic running natty userspace, and so far it seems to be working ok in either internal, external, or mirrored mode. In side-by-side mode I have trouble with regions of the screen appearing black but I suspect that is actually a Unity bug separate from X. (Have not tested in classic mode yet.)

[Martin Pool (mbp)]

From Bryce's #29, I tested acelan's kernel from http://people.canonical.com/~acelan/bugs/lp753189/ linux-image-2.6.38-8-generic

At first this looked promising because the machine did start up with both displays working, and I could switch it to using only the external display. However, after toggling through setups a few times using Fn-F7, eventually the machine got stuck with neither display active; after about ten seconds in that state in spontaneously powered down.

[Martin Pool (mbp)]

Oneiric's 2.6.39-3-generic by contrast seems robust across multiple mode switches. In 2d classic (metacity) mode, it does not have any problems with black areas on the screen.

[Martin Pool (mbp)]

tjaalton and bryceh suggested bisecting using the packages built from mainline rather than building from scratch.

Using <http://kernel.ubuntu.com/~kernel-ppa/mainline/>

v2.6.39-rc1-natty when the external monitor is plugged in will _only_ use the external monitor; the monitors control panel apparently cannot even detect the internal monitor. If I unplug the displayport cable the internal screen is stuck black.

v2.6.39-rc4-natty seems to work correctly.

rc2 apparently failed to build.

[Martin Pool (mbp)]

and rc3 also seems ok.

I will try again on a bisect between rc1 and rc3.

[Martin Pool (mbp)]

rc4 shows some visual corruption after resume from suspend, which can be cleared off by going to vt1 and back.

"git bisect start v2.6.39-rc1 v2.6.39-rc4 drivers/gpu/drm"

[Martin Pool (mbp)]

The fix seems to be prior to upstream 9bb09fa1b5b07459279301ac6220d575f307597b

[Martin Pool (mbp)]

7f58aabc369014fda3a4a33604ba0a1b63b941ac shows some flickering on the external monitor when first logging in to metacity/classic, but it does work reliably in all modes.

[Martin Pool (mbp)]

6ee3b5a12740eddc5a76e130b6cc7cc64468d1f7 also seems ok, and according to git bisect that might be the patch that fixes it. From the description it seems somewhat plausible. I am going to try one of the parent revisions too and see if they reliably break.

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=6ee3b5a12740eddc5a76e130b6cc7cc64468d1f7

[Martin Pool (mbp)]

On f0c8602 which is the immediate parent of this revision, when I boot with an external screen attached, I don't see any display on the internal panel, and it doesn't show up in the monitors control panel. That's the same breakage I described affecting rc1 in comment 57. So this is at least one useful fix. It seems like this is not the only fix we need, since failing to enable the internal LVDS panel is only one of the problems here.

Bryce, any advice on what to try next?

[Timo Aaltonen (tjaalton)]

http://kernel.ubuntu.com/git?p=lexical/lexical-natty.git;a=shortlog;h=refs/heads/lp788026

if you need more than those, please let us know

[Martin Pool (mbp)]

Ubuntu-2.6.38-9.43-8-g930a188 from that branch seems to work well for me, thanks!

[Martin Pool (mbp)]

I spoke a bit too soon.

Timo's branch is a bit better in that the external display works, but not quite right. Some observations:

 * booting with the external display connected shows the boot and login screens on both, and then my session comes up only on the external display
 * I can use the monitor preferences panel to reconfigure them
 * Fn-F7 has no effect (istr we discussed on irc that this was fixed by something else in .39)
 * If I disconnect with the display already set to internal only, it's ok
 * If I disconnect the laptop (either the dp cable or from the base) with the internal display turned off, it does not turn back on and (per above) I can't bring it back on with Fn-F7, nor by switching to vt1 and back
 * On resume from suspend, neither panel shows anything. The internal display backlight comes on but there's no content.

[Martin Pool (mbp)]

I put an amd64 package of that branch into <http://sourcefrog.net/tmp/1y/745112/> in case other people want to try it.

[Martin Pool (mbp)]

If you want me to test anything else, or bisect between two particular points, let me know.

[Timo Aaltonen (tjaalton)]

Martin, thanks for testing! I meant building the whole branch, which is what you did. Now we'll need to add the backported patches to the SRU queue.

[Timo Aaltonen (tjaalton)]

Duh, didn't read but the couple of last comments. So it would be nice to know which of these bugs are regressions due to these patches, and which have been there before.

[Michael Hudson-Doyle (mwhudson)]

I've had a pretty confusing time trying to get my new x220 working with an external display. Using Martin's packages, I have the external monitor working when the internal display is blanked (through an ultrabase, but I don't /think/ that's making a difference). Happy to test kernels with proposed fixes, but probably not until next week.

[Jean-Philippe Toupin (jptoupin)]

Martin's packages also got the external display working for me.

[Martin Pool (mbp)]

That package does have the drawback that suspend/resume is broken: the
machine sits there with the screen (or both screens) off, and
unresponsive to keyboard input. This was working correctly in the
stock natty packages.

[T Martin (mortramalt)]

I'm still curious why it would be that the issue isn't present in a clean
install of Xubuntu 11.04, but is a problem with Ubuntu 11.04, Fedora 15, and
Linux Mint 11.

On Sun, Jun 12, 2011 at 19:32, Martin Pool <email address hidden> wrote:

> That package does have the drawback that suspend/resume is broken: the
> machine sits there with the screen (or both screens) off, and
> unresponsive to keyboard input. This was working correctly in the
> stock natty packages.
>
> --
> You received this bug notification because you are subscribed to a
> duplicate bug report (771713).
> https://bugs.launchpad.net/bugs/745112
>
> Title:
> [arrandale] desktop is messed up (goes black) when laptop is docked
> with two external 1920x1200 monitors (x86_64)
>
> Status in X.org xf86-video-intel:
> Incomplete
> Status in “linux” package in Ubuntu:
> Triaged
> Status in “xserver-xorg-video-intel” package in Ubuntu:
> In Progress
>
> Bug description:
> Binary package hint: unity
>
> (I'm not sure where in the stack this problem really is, so I'm
> guessing and picking on unity)
>
> I have a Lenovo T410s laptop with Intel graphics and I use it with a
> dock with two 1920x1200 monitors connected. I'm running up-to-date
> Natty. If I boot the laptop with it already docked, everything works
> perfectly: the two external monitors are used and I get a nice unity
> desktop spanning my 3840x1200 space.
>
> However, if I boot with the laptop undocked, log in, and then dock the
> laptop, it breaks pretty badly. Only one monitor is lit up, and I
> just get a black screen with a mouse pointer there -- no desktop
> background, windows, toolbars, or anything. Once it's in this state,
> it doesn't seem possible to recover -- if I undock the laptop again,
> the internal screen just stays black with a pointer.
>
> When the laptop is in a working state, undocking it sort of works...
> the desktop switches to the laptop screen, but then redocking it acts
> just like docking as described above.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 11.04
> Package: unity 3.6.8-0ubuntu3
> ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
> Uname: Linux 2.6.38-7-generic x86_64
> Architecture: amd64
> CompizPlugins:
> [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,scale,session,unityshell]
> CompositorRunning: compiz
> DRM.card0.DP.1:
> status: disconnected
> enabled: disabled
> dpms: Off
> modes:
> edid-base64:
> DRM.card0.DP.2:
> status: disconnected
> enabled: disabled
> dpms: Off
> modes:
> edid-base64:
> DRM.card0.DP.3:
> status: disconnected
> enabled: disabled
> dpms: Off
> modes:
> edid-base64:
> DRM.card0.HDMI.A.1:
> status: disconnected
> enabled: disabled
> dpms: Off
> modes:
> edid-base64:
> DRM.card0.HDMI.A.2:
> status: connected
> enabled: enabled
> dpms: On
> modes: 1920x1200 1920x1080 1920x1080 1600x1200 1680x1050 1400x1050
> 1280x1024 1280x1024 1440x900 1360x768 1152x864 1280x720 1280x720 1024x768
> 1024x768 1024x768 832x624 800x600 800x600 800x600 800x600 720...

[Zak Kipling (zak-k)]

For me (on a Thinkpad x201), it appears that this commit causes the hang on resume:

   drm/i915: Use ACPI OpRegion to determine lid status

I'm using the current Natty kernel (v2.6.38-8.42) plus the drm/i915 changes from the Ubuntu git repo for 2.6.38-9 and -10, plus the patches in the branch Timo referred to above, EXCEPT for the above patch and those which don't apply cleanly without it:

  drm/i915: Move the lvds OpRegion lid detection code to panel and reuse for eDP
  drm/i915/lvds: Always return connected in the absence of better information

Suspend/resume, all combinations of internal panel and external VGA, and Fn+F7 are now all working.

[Zak Kipling (zak-k)]

And, rebasing, 2.6.38-10.44 from natty-proposed + the following patches also works well for me:

UBUNTU: SAUCE: drm/i915: disable PCH ports if needed when disabling a CRTC (modified)
drm/i915: Busy-spin wait_for condittion in atomic contexts
drm/i915: Reset GMBUS controller after NAK
drm/i915/crt: Remove 0xa0 probe for VGA
drm/i915/lvds: Remove 0xa0 probe for LVDS

(I haven't checked which of those five patches are required though.)

[Zak Kipling (zak-k)]

The one thing which is still troublesome is disconnecting the external VGA while suspended, leaving the internal display blank on resume. However this was always flaky in maverick, and is easily fixed by switching to a text console and back.

(I don't have a docking unit available to test other outputs though.)

[Michele (mikelito)]

Zak, if you can point me to a PPA with your patched kernel, I'd be glad to test it with a docking station and report back.

[Timo Aaltonen (tjaalton)]

Here's a newer kernel with just one commit backported. It seems to make things more or less functional on a sandybridge system, so please try it out to see if there are regressions to the stock natty kernel, or to the one with more backported stuff:

http://people.canonical.com/~lexical/bugs/lp791752/

[Michele (mikelito)]

I installed the kernel posted by Timo, and so far I am pretty happy with it.
Let me test it for a few days, though: on my machine (thinkpad t410) these crashes are a bit erratic.
This is what I tested so far:

Booted docked -> correctly shows both LVDS and external monitor
undocked -> correctly updates monitors to display only LVDS
re-docked -> updates and shows both LVDS and external monitor
suspended docked, undocked, resumed -> black screen. fixed by switching to console and back
suspended undocked, docked, resumed -> shows both LVDS and external monitor correctly.

I'll let you know if the fix is really stable.
Thanks for the effort fixing this annoying bug.

[wahlau (wahlau)]

using the backport kernel from Timo, with the t410s connected directly to a Samsung 225BW i still get random switching from LVDS alone to dual display. I do see some improvements - my screen do not switch off and on that frequently as compared to default latest kernel, but problem is not solved.

[Zak Kipling (zak-k)]

I've re-tested with just the one patch as per Timo's comment above; this seems to work just as well for me as my previous test with the additional patches.

[Michael Hudson-Doyle (mwhudson)]

On my x220, I would agree that Timo's kernel is at least as good as any of the others I've tried (Martin's, 3.0.1.2 from oneiric). Suspend and resume works. Trying to enable both monitors leaves large black areas that are not drawn into, but I think that might be a unity problem.

The summary of this bug seems to no longer reflect what is being discussed (arrandale vs sandy bridge, desktop vs external) -- is it really the same problem?

[Martin Pool (mbp)]

I tried this on my x201 against an Optoma projector and it seems to basically work. (I'm not at home with my monitor at the moment.)

I do see the black areas but I agree that's likely a unity thing, or at least not a modesetting bug.

Fn-F7 does not work.

[Martin Pool (mbp)]

Using Timo's linux-image-2.6.38-10-generic_2.6.38-10.44sru1_amd64.deb, with my regular external monitor mentioned above: so far so good.

[Timo Aaltonen (tjaalton)]

Thank you for testing. I consider this fixed in oneiric, and continuing to follow this on natty.

[Timo Aaltonen (tjaalton)]

closing the driver task, this was a kernel issue.

[Martin Pool (mbp)]

One remaining problem with Timo's kernel is that Fn-F7 does not work, which amongst other things means if the laptop ever gets confused with the internal display off there is no escape other than hard-rebooting.

[Martin Pool (mbp)]

One other issue (though it might be compiz rather than the kernel) is that after ejecting and then re-docking I'm left with a screen that's totally blank aside from a mouse cursor. The cursor moves with the mouse and it actually changes shape from arrow to I-bar to finger as I move around, suggesting the windows are still there, but the lights are out.

[Timo Aaltonen (tjaalton)]

Martin: That is indeed a compiz bug.

Fn-F7 not working; weird that for some X201's it does work but not for you. Don't know why. Has it ever worked?

[Martin Pool (mbp)]

The black-screen issue has happened more than once, but I don't yet know how to consistently reproduce it. It is different to (though maybe related) to the other issue seen where some regions of the screen aren't drawn correctly.

[Martin Pool (mbp)]

It worked perfectly in previous Ubuntu releases.

It's also worked in some of the kernel I've tried in the course of
trying to localize this bug.

[Martin Pool (mbp)]

One more thing, which also worked ok before: after coming back from resume, there is out-of-sync noise on the external monitor. Switching to vt1 and back fixes it, which suggests to me it's also mode-setting related.

[Michael Hudson-Doyle (mwhudson)]

I built a kernel at http://people.linaro.org/~mwh/x220 with Timo's fix (and also the fix for bug 761065) after today's natty update. It seems to work for me, but I'm extremely new to building kernels so please don't be too surprised if it breaks.

[Marko Vendelin (marko-vendelin)]

I am using Thinkpad X201 (natty, unity) with docking station and an external monitor attached via DP -> HDMI. Note that I have packed all additional files (screenshots, logs) into tar.bz2 attached below.

Since I had problems with the external monitor (occasional black monitor on boot ...), I started using Timo's kernel ( linux-image-2.6.38-10-generic_2.6.38-10.44sru1_amd64.deb ). In my setup, the laptop screen is off and all work is done via external monitor. Probably after running the screensaver, the monitor got corrupted with the several regions just shown in black. It seems that during a wakeup, external screen was run as if it is the internal laptop screen. This can be observed on attached screenshots with terminal occupying part of the screen (Screenshot1.png) or maximized ( Screenshot-terminal-fullscreen.png ). On other desktops, all maximized windows were reduced accordingly. Monitor preferences ( Screenshot-monitor-preferences.png ) seem to confirm it; xrandr and dmesg outputs are in xrandr.txt and dmesg.beforexrandr.txt, correspondingly. I managed to fix the problem by running

xrandr --output LVDS1 --auto
xrandr --output LVDS1 --auto --output HDMI1 --auto
xrandr --output LVDS1 --auto --output HDMI1 --off
xrandr --output LVDS1 --auto --output HDMI1 --auto
xrandr --output LVDS1 --auto --output HDMI1 --auto --primary

As a result, I returned to my setup. If I remember correctly, LVDS1 was actually off after running all those commands and looking at 'Monitor Preferences' (Screenshot-monitor-preferences.png). Dmesg after all those commands is in dmesg.afterxrandr.txt .

In addition, I have attached part of kern.log from my last boot (first 60s). If the full log is needed (~700KB), it can be downloaded via http://sysbio.ioc.ee/~markov/kern.log.full.bz2

Let me know if I should report this bug somewhere else and if you have any questions.

[matthew (mattwindwer)]

I was having similar problems with my Thinkpad T410 (external monitor connected via display port would be blank after logging in). I realized that I keep my monitor off until I reach the ubuntu login screen, then turn it on, then log in, the external monitor always works.

[Stephan Windmüller (stephan-windmueller)]

Timo's packages from comment #79 work for me, too. However, the kernel update which came today is marked as newer based on the version number but does not contain the fix.

[Timo Aaltonen (tjaalton)]

The backported commit caused bug 814325, so it's likely going to be pulled before the kernel hits natty-updates.

[Timo Aaltonen (tjaalton)]

Actually no, the patch got through proposed and is now in -updates :)

[Stephan Windmüller (stephan-windmueller)]

linux-image-2.6.38-11-generic fixed it for me in natty. Thank you!

[Kai Spindler (kaiwasaki)]

linux-image-2.6.38-11-generic
Doesn't work for me i get a black screen on my laptop monitor. With an external monitor I can see the background image but i can't start any application, but the system is not frozen i can change to tty1-(...).

[Joe Thomas (joewilliamthomas)]

linux-image-2.6.38-11-generic Also doesn't work for me.
However as mentioned in a comment above this only seems to affect me when the monitor is already plugged in when I start up Ubuntu.
If I boot up Ubuntu without an external monitor, then plug in a screen, it works fine.

[Martin Pool (mbp)]

This bug, or one a lot like it, seems to have regressed on oneiric (3.0.0-11). If I boot up my x201 with the external monitor connected, it normally but not always works. When it comes back from the screensaver, normally the external screen will be blank but switching to vt1 and back does get the screen back (showing the unlock dialog.) If I connect the screen after the machine has booted, both the internal and external display are persistently black. In this case switching to vt1 does show a text login prompt, but switching back to vt7 just makes them both black again.

[Martin Pool (mbp)]

Current oneiric seems pretty consistent: if the external monitor is connected when the machine is turned on or comes back from suspend, it works. If the machine is inserted in to the dock while powered on, and then the external display is activated, it doesn't set the right mode and it does not work.

[Martin Pool (mbp)]

As of current oneiric, external displays on this machine seem totally broken, even if the machine is booted up with the display attached: worse than a week ago.

[mrlarkin (mrlarkin)]

I can confirm heavy problems with oneiric. My Laptop (Lenovo X201s on a docking station) is connected via display port to a 19" Dell screen. This screen stays black when I activate it via gnome or fn+f7. Sometimes (i.e. not reproducible) the screen gets a signal after multiple rounds of pressing fn+f7 (~20 times).
Rebooting the laptop with the monitor switched off an switching on when I am logged in again does not help at all.

In dmesg the following logs appear:
[ 150.471512] [drm] Changing LVDS panel from (-hsync, -vsync) to (-hsync, +vsync)
[ 151.315930] [drm:intel_dp_complete_link_train] *ERROR* failed to train DP, aborting
[ 152.325743] [drm] Changing LVDS panel from (-hsync, +vsync) to (-hsync, -vsync)
[ 153.441943] [drm:intel_dp_complete_link_train] *ERROR* failed to train DP, aborting
[ 155.196290] [drm:intel_dp_complete_link_train] *ERROR* failed to train DP, aborting
[ 171.041755] [drm:intel_dp_i2c_aux_ch] *ERROR* too many retries, giving up

I will provide further information as needed.

[Martin Pool (mbp)]

As of today, it sometimes works, but it's hard to characterize when it does and when it does not. Generally speaking docking the laptop while it's powered on is problematic.

[Timo Aaltonen (tjaalton)]

Martin: might help doing another round of mainline kernel testing..

http://kernel.ubuntu.com/~kernel-ppa/mainline/

no other suggestion ATM

[Martin Pool (mbp)]

I tested with 3.2.0-030200rc1, and external displayport seems roughly equally broken there: if I boot up the laptop with it connected it usually works; if I try to connect it afterwards it generally doesn't work.

vga seems to work reasonably well through either the directly onboard vga or through the dock's vga connector, though it since it has some analog noise on the screen it's not a great solution.

[Martin Pool (mbp)]

OK, so kernel 3.2.0-030200rc1 seems to consistently behave like this:
 * boot up an x201 docked with dp connected to an external monitor
 * grub appears on both screens
 * plymouth appears on both screens
 * lightdm appears on both screens in low-res mirrored mode
 * unity session comes up with both screens blank
 * fn-f7 can get it back to mirrored mode
 * trying to switch to the external monitor does not work

What does work is, from the displays panel:
 * turn on both in mirrored mode
 * then turn off mirrored mode, but leave the external panel at a low resolution
 * set it to 1920x1440, and apply
 * then change to 2560x1600 and apply

so there is some path-dependency: full resolution will only work if you previously set it to a lower resolution.

i hope that helps.

[Martin Pool (mbp)]

steve langasek says

> BTW, your Arrandale DisplayPort issues are probably fixed in the
> drm-intel-next tree, given that Keith has been working on these exact issues
> recently.  You might want to give this kernel a try:
>
>  git://people.freedesktop.org/~keithp/linux drm-intel-next
>
> (AFAIK we don't have autobuilt packages from this, sorry)

[Martin Pool (mbp)]

chipaca suggested I could packages of that kernel from http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next/

with Linux joy 3.1.0-997-generic #201111170422 from there, I get the same behaviour I described in comment#110.

[Alik (kilaka)]

I recently got an update from xorg-video-intel and it seems to work using an external monitor at home. I have another external monitor at work, so i'll test it further tomorrow.

[Alik (kilaka)]

Worked only one time :(

[Martin Pool (mbp)]

With today's updates I also had things just come up and work in the correct resolution. I hope it lasts.

[Martin Pool (mbp)]

https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/906086 for similar but different problems on precise.

[Martin Pool (mbp)]

Current Precise still has this bug. I also tried with the current drm-intel-next kernel from <http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next/2012-01-05-precise/> and I had the same problem.

Bug 906086 is about a kernel oops when trying to use the external display. I have not seen that recently, but the description from the upstream suggests it may be intermittent (it's a use-after-free bug.)

[Martin Pool (mbp)]

Forwarded from

"[arrandale] desktop is messed up with external monitors (x86_64)" [Critical,Triaged] https://launchpad.net/bugs/745112
(which has various hardware info, etc)

On a Thinkpad X201, external monitors can reliably set low-resolution modes (eg 1280x800), but at higher resolutions they apparently do not set the right sync lines and the monitor goes black.

In some cases, it works correctly if you first set a low resolution and then gradually step up, but this does not work reliably.

I can reproduce this in the current build from http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next/2012-01-05-precise/

Linux joy 3.2.0-997-generic #201201050433 SMP Thu Jan 5 09:34:48 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

[Martin Pool (mbp)]

Sent upstream in https://bugs.freedesktop.org/show_bug.cgi?id=45211

(Please attach that to this bug if you can work out how...)

[Martin Pool (mbp)]

I'm very happy to test or debug things here, if someone gives me a pointer where to start.

[Daniel-ffwll (daniel-ffwll)]

Please attach xrandr --verbose output. Also please boot with drm.debug=0xe attached to your kernel cmdline, try to set a low working resolution and then a high non-working resolution and attach the entire dmesg. Please ensure that the attached dmesg is complete, if stuff at the beginning is missing you need to increase the log buffer with log_buf_len=2M or even larger.

Also please provide the output of lspci -nn for you gpu.

[Daniel-ffwll (daniel-ffwll)]

Chris Wilson also reports occasional (really occasionl) transcoder failures on his x201 at the same resolution.

[Daniel-ffwll (daniel-ffwll)]

Turning of audio might help, can you please try this:

xrandr --output DP1 --set audio off

[Martin Pool (mbp)]

it looks like bugs.freedesktop.org is down at the moment, so I'll attach them in lp.

[Martin Pool (mbp)]

lspci -vvnn output

[Martin Pool (mbp)]

xrandr --verbose output

[Martin Pool (mbp)]

This kernel log shows it:

 * initially coming up in mirrored mode, successfully
 * trying to set it to 2560x1600 and having the external monitor blank
 * then gradually stepping up the external monitor to 1920x1080 (where it works) and then 1920x1200 (where it doesn't work)

[Martin Pool (mbp)]

Hi, here is the requested information:

 https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/745112/+attachment/2700631/+files/x201-lspci.txt

 https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/745112/+attachment/2700632/+files/x201-dell30-xrandr.txt

 https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/745112/+attachment/2700641/+files/x201-kernel.txt

[Martin Pool (mbp)]

> xrandr --output DP1 --set audio off

looks good:

I plugged my laptop into the dock, and it came up at the medium
resolution it was running at earlier in the day. I ran that command,
and the screen blanked briefly, I guess while the dp link was
reestablished. I then used the displays panel to switch up to full
resolution and it worked.

So, 1/1. But, this has always been a bit intermittent, so more
testing might be needed.

[Martin Pool (mbp)]

Hitting Fn-F7 a few more times, I still have the blank screen problem,
and turning dp audio off again does not fix it.

[Martin Pool (mbp)]

I've tried, as a bit of a shot in the dark, cutting out one bit of code that seems to try to enable the audio pipe, and this does not seem to be enough to make it reliable when the display is configured automatically.

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index db3b461..007c68b 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -867,10 +867,14 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
                break;
        }
        if (intel_dp->has_audio) {
- DRM_DEBUG_DRIVER("Enabling DP audio on pipe %c\n",
- pipe_name(intel_crtc->pipe));
- intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;
- intel_write_eld(encoder, adjusted_mode);
+ if (1) {
+ DRM_DEBUG_DRIVER("DP audio forced off!\n");
+ } else {
+ DRM_DEBUG_DRIVER("Enabling DP audio on pipe %c\n",
+ pipe_name(intel_crtc->pipe));
+ intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;
+ intel_write_eld(encoder, adjusted_mode);
+ }
        }
        memset(intel_dp->link_configuration, 0, DP_LINK_CONFIGURATION_SIZE);
        intel_dp->link_configuration[0] = intel_dp->link_bw;

[Martin Pool (mbp)]

I tried the current tip of drm-intel-next-fixes (44306ab302687b519a31aa498b954c1e26f95a6b) and it has the same problem.

[Martin Pool (mbp)]

It seems like if I force audio off at the same time I add the external screen, through xrandr, it does work reliably(?) so far. Using the monitor control panel or fn-f7 apparently puts audio back to the 'auto' setting, which does induce a problem

I tried running

for i in `seq 30` ;do; echo i && xrandr --output DP1 --off && sleep 15 && xrandr --output DP1 --mode 2560x1600 --above LVDS1 --set audio off && sleep 15 || break;done

and this got through 14 iterations successfully.

Now I wonder if I can identify what the problem is with audio or provide a way to force it off. This screen does have an option for speakers to be connected, but I'm not using it. I don't know if it picks up audio across dp.

[Martin Pool (mbp)]

Running

xrandr --output DP1 --mode 2560x1600 --above LVDS1 --set audio on

when it's previously working does immediately make the monitor black out, and using '--set audio off' does not bring it back, nor does soft power cycling the monitor or unplugging/replugging it.

I can see some reports of people complaining about dp/audio problems under windows with the U3011, but it's hard to tell how much they indicate a real hardware/firmware problem vs windows driver problems or something else.

http://en.community.dell.com/support-forums/laptop/f/3517/p/19370516/19844480.aspx

> It seems that the Nvidia based implementation at least with Displayport "++" out will only support an audio signal being passed over displayport to an external monitor that is no high resolution than 1080HD, or 1920x1080.

So I wonder if there is some way for Linux to know not to try this, preferably without needing special user configuration:

 * don't do audio above a certain resolution?
 * ... on specific hardware models?
 * don't do DP audio at all by default?

[Martin Pool (mbp)]

I tried a couple of variations on that patch to try to force dp audio off, with no success. If someone gives me a patch or an idea on where to start I'm happy to try it.

[Martin Pool (mbp)]

Just to be clear: forcing audio off every time the external display is configured, by using "xrandr ... --set audio off", does make it work reliably every time so far.

What I tested previously, and what did not work to turn it off just once and then use the system's normal configuration method (eg fn-f7), I guess because that is effectively configuring the monitor with auto audio.

So it does seem that the problem is related to audio; in my particular situation being able to force it off all the time would at least hide the problem. I don't care about sending audio to my monitor, but I suppose others do, so a patch that just turns it off across the board probably wouldn't be accepted.

I guess the next thing to work out is:

 * audio actually can't work on this channel with this resolution (not enough bandwidth?)
 * there's a bug in this monitor to do with audio at high resolution?
 * there's some other bug in the kernel about dp audio?
 * ...?

[Martin Pool (mbp)]

The problem i describe in <https://bugs.freedesktop.org/show_bug.cgi?id=45211#c16>, coming up with only a restricted set of resolutions available, seems connected to booting in 'recovery' mode and then proceeding to a normal desktop.

Leaving that aside, with the one patch from <https://git.kernel.org/?p=linux/kernel/git/keithp/linux.git;a=commitdiff;h=c898261c0dad617f0f1080bedc02d507a2fcfb92> applied to the Ubuntu Precise kernel it looks like things are working ok.

[Martin Pool (mbp)]

Now that I know not to use recovery mode (which might be a separate less important bug), <http://people.canonical.com/~ogasawara/fdo44881/amd64/cmt3/> does work for me.

[Martin Pool (mbp)]

And <https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/745112/+attachment/2725463/+files/2012-02-09-intel-dp-oneiric.diff> looks like it works as a (not quite trivial) backport of the fix to 3.0.17.

[Martin Pool (mbp)]

the current tip of drm-intel-fixes does seem to have this fixed (but drm-intel-next-fixes does not)

[Martin Pool (mbp)]

so perhaps the fix for https://bugs.freedesktop.org/show_bug.cgi?id=44881
c898261c0dad617f0f1080bedc02d507a2fcfb92

will also fix this...

[Martin Pool (mbp)]

Ogasawara's build http://people.canonical.com/~ogasawara/fdo44881/amd64/cmt3/ from bug 44881 is only partly working for me: the external monitor does come up, but only at 1600x1200 and xrandr shows
                                                         mbp@joy% xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 640 x 480, current 1600 x 1200, maximum 1600 x 1200
default connected 1600x1200+0+0 0mm x 0mm
   1600x1200 0.0*
   1280x1024 0.0
   1024x768 0.0
   800x600 0.0
   640x480 0.0

[Martin Pool (mbp)]

http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next/2012-01-05-precise/linux-image-3.2.0-997-generic_3.2.0-997.201201050433_amd64.deb
does seem to work correctly.

I'm going to try what I think is the right patch applied to the precise kernel.

[Martin Pool (mbp)]

I built Ubuntu-3.2.0-15.24
from git://kernel.ubuntu.com/ubuntu/ubuntu-precise.git plus
https://git.kernel.org/?p=linux/kernel/git/keithp/linux.git;a=commitdiff;h=c898261c0dad617f0f1080bedc02d507a2fcfb92
and that does seem to fix the problem, hooray. Maybe that one fix can be cherrypicked into the Ubuntu kernel?

The binary is in http://sourcefrog.net/tmp/1m/linux-image-3.2.5-drm-mbp4+_3.2.5-drm-mbp4-mbp0_amd64.deb

(I think the wonky version number is just due to mixing make-kpkg and a debian-style tree?)

I'm going to see if it will work on Oneiric too, and perhaps also do a clean build of it.

[Martin Pool (mbp)]

Here's an attempted backport of that patch to the oneiric kernel; not tested yet.

[Martin Pool (mbp)]

on precise, <http://people.canonical.com/~ogasawara/fdo44881/amd64/cmt3/> does seem to be working correctly

on oneiric's kernel, <https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/745112/+attachment/2725463/+files/2012-02-09-intel-dp-oneiric.diff> seems to fix it, and there is a binary from that in <http://sourcefrog.net/tmp/1m/linux-image-3.0.17-oneiric-mbp5+_3.0.17-oneiric-mbp5-mbp0_amd64.deb>

[Daniel-ffwll (daniel-ffwll)]

If drm-intel-fixes works flawless, but just backporting the patch does not yet work so great, we likely miss a few of the recent dp fixes in -stable trees.

Closing this, please reopen if it shows up again or file a new bug reporter if you still have other issues left.

[Leann Ogasawara (leannogasawara)]

Hi Martin,

Thanks for all the extra testing and feedback. I'd been looking at bug 912387 (fdo bug 44881) in parallel. The patch to fix bug 912387 appears to provide a fix for the issue you are seeing here. I've therefore cherry-pick'ed the patch in question from the drm-intel-fixes branch into Precise prior to the patch officially hitting the mainline kernel. So this issue should be resolved in Precise after the next upload (which I intend to do before the end of the week).

I see that the patch has also been CC'd to upstream stable. Once the patch does land in mainline, it'll then propagate through to the upstream stable releases. This means that it should land in Oneiric automatically through our normal SRU process and not require any further action on our part. Thanks.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.2.0-16.25

---------------
linux (3.2.0-16.25) precise; urgency=low

  [ Andy Whitcroft ]

  * d-i -- include the Hyper-V drivers in the virtio udeb
    - LP: #917135

  [ Felix Fietkau ]

  * (pre-stable): ath9k_hw: fix a RTS/CTS timeout regression
    - LP: #925602

  [ Keith Packard ]

  * SAUCE: drm/i915: Force explicit bpp selection for
    intel_dp_link_required
    - LP: #745112, #912387, #917330

  [ Leann Ogasawara ]

  * Fix typo in generic-pae description
    - LP: #928448
  * Rebase to v3.2.6

  [ Upstream Kernel Changes ]

  * procfs: parse mount options
    - CVE-2011-4917
  * procfs: add hidepid= and gid= mount options
    - CVE-2011-4917
  * proc: fix null pointer deref in proc_pid_permission()
    - CVE-2011-4917
  * xhci: Remove warnings about MSI and MSI-X capabilities.
    - LP: #929656
  * xhci: Remove scary warnings about transfer issues.
    - LP: #929656
  * x86, mce, therm_throt: Don't report power limit and package level
    thermal throttle events in mcelog
    - LP: #930288
  * rebase to v3.2.6
    - LP: #924320
    - LP: #918254
 -- Leann Ogasawara <email address hidden> Mon, 13 Feb 2012 13:00:08 -0800

[Martin Pool (mbp)]

Thanks, Leann.

I have just tried 3.2.0-16.25 and it's not completely working, the external monitor is still black at high resolutions. I'll investigate some more.

[Martin Pool (mbp)]

One apparently regression in 3.2.0-16.25 (maybe unconnected to this change?) is that fn-f7 does not seem to have any effect. It was working on the previous kernel I tried, both the Ubuntu ones and my own builds.

Turning on the external screen with xrandr does work:

xrandr --output DP1 --mode 2560x1600 --set audio off --above LVDS1

Using the displays control panel, the first time I tried, the monitor showed an error about the signal being wrong. I've just tried again and it has worked. So, I'm not sure. Also, after using the monitors control panel, Fn-F7 is working again. (So, perhaps the bug is in userspace?) I'll see if I can get a better description of what the problem is.

[Martin Pool (mbp)]

This is definitely improved but not fixed. Most of the time the external monitor comes up ok, but sometimes when I switch a running session on to the external monitor it stays irretrievably blank. Here's a kernel log with debugging on of those transitions.

I have not yet worked out the pattern or a reliable reproduction.

[Martin Pool (mbp)]

Current status in Precise seems to be:

 - works reliably with ` xrandr --output DP1 --mode 2560x1600 --set audio off`
 - fairly reliably **does not** work if I set the external monitor direct to 2560x1600 from the monitors control panel, I'm guessing because that does auto audio and gets it wrong.

[Martin Pool (mbp)]

Using the current kernel from Precise, which is supposed to have the latest patches, my external monitor works if audio is forced off using xrandr, but fails if audio is left in auto mode. So, reopening.

[Timo Aaltonen (tjaalton)]

On Sat, 10 Mar 2012, Martin Pool wrote:

> Using the current kernel from Precise, which is supposed to have the
> latest patches, my external monitor works if audio is forced off using
> xrandr, but fails if audio is left in auto mode. So, reopening.

please follow up on the upstream bug as well

[Martin Pool (mbp)]

That comment was on the upstream bug, Launchpad just forwarded it to you ;)

[Martin Pool (mbp)]

On Ubuntu's current kernel (3.2.0-20-generic #32-Ubuntu SMP Thu Mar 22 02:22:46 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux), the behaviour is:

 * after booting, the machine comes up ok to the lightdm screen, and after logging in it restores the previous configuration correctly, ie external monitor at full resolution and internal screen off
 * if I log out, both screens go black and stay black

[Jesse Barnes (jbarnes-virtuousgeek)]

Two things may be going on here:
  1) we're setting the DP audio enable bit too early I think; we should only set it when we go to a normal link mode
  2) there may not be enough bw for audio at 25x16 with the clock configuration we use, we may need to reduce the audio config somehow

Paulo, do you have a DP monitor you can test with to confirm?

I just confirmed that 25x16 works fine on my ILK laptop with drm-intel-next-queued, but I don't have any audio in my config.

Martin, it would be good if you could re-test with drm-intel-next-queued too, just to rule out recent fixes (there have been a number that might affect this).

[Timo Aaltonen (tjaalton)]

Martin: here's a kernel build with that branch:

http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-experimental/current/

(d-i-e mapped to d-i-n-q)

[Daniel-ffwll (daniel-ffwll)]

Is this still an issue on 3.6-rc kernels?

[Timo Aaltonen (tjaalton)]

Please test with 3.6-rc kernel from http://kernel.ubuntu.com/~kernel-ppa/mainline/

[Chris Wilson (ickle)]

Timeout. Please do reopen if you can still reproduce the issue and help us diagnose the problem, thanks.

[Martin Pool (mbp)]

I have tried this screen and machine with 3.6 and so far it seems to be
working.

Martin
On Oct 22, 2012 1:30 AM, <email address hidden> wrote:

> Chris Wilson <email address hidden> changed bug 45211<https://bugs.freedesktop.org/show_bug.cgi?id=45211>
> What Removed Added Status NEEDINFO RESOLVED Resolution --- INVALID
>
> *Comment # 24 <https://bugs.freedesktop.org/show_bug.cgi?id=45211#c24>on bug
> 45211 <https://bugs.freedesktop.org/show_bug.cgi?id=45211> from Chris
> Wilson <email address hidden> *
>
> Timeout. Please do reopen if you can still reproduce the issue and help us
> diagnose the problem, thanks.
>
> ------------------------------
> You are receiving this mail because:
>
> - You reported the bug.
>
>

[Daniel-ffwll (daniel-ffwll)]

Marking as fixed then, pls reopen if it blows up again, and thanks for submitting the status update.

[psny18 (psny18)]

I'm not sure if I'm in the right place, but on my T61 + docking station I have an issue with desktop files/folders not being displayed correctly. With either VGA or DVI, everything works great but the files/folders in the Desktop/ folder are not constrained to the viewable area. They remain on the laptop monitor (can be dragged to the external monitor) but they are off the screen. "Organize Desktop by Name" has the same result.

So, it seems that the area allocated to icons is bigger than the actual display.

[psny18 (psny18)]

sorry, forgot my details
12.04 LTS x86_64 with 3.2.0-34-generic

[Timo Aaltonen (tjaalton)]

closing as wontfix for precise, it'll get in a point release anyway and the fixing commit is very hard to identify