[i915] no valid modes on LVDS / ASUS M6A notebook

[MichalM]

Tried with latest packages of Ubuntu 9.04 Alpha 4 - Xorg won't start in hi-res mode. Starts only with VESA driver in 800x600.

Lines from Xorg.log:
[ 1.321393] (EE) intel(0): Output LVDS enabled but has no modes
[ 1.321456] (EE) intel(0): No valid modes.

This didn't work with Ubuntu 8.10 neither. Last working is the LTS release of 8.04.

HW:
ASUS M6A notebook
Intel 915G chipset

00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)
00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)

I'll attach complete xorg.log.

[MichalM (jafa81)]

xorg driver is version is:
xserver-xorg-video-intel 2:2.6.1-1ubuntu2

[Geir Ove Myhr (gomyhr)]

Thank you for reporting this bug and helping to make ubuntu better. It seems like this is an issue with the EDID information the LVDS display sends. Could you attach something which contains this. Either the output of `xrandr --verbose` or simply the Xorg.0.log of an updated jaunty (the newest Jaunty automatically logs this information, but alpha-4 didn't).

[MichalM (jafa81)]

New Xorg.0.log as requested....
Thanks!

[Geir Ove Myhr (gomyhr)]

MichaL, it seems that the new Xorg.0.log does not contain the EDID information, which I think means that xorg does not get it (and this is probably the source of the problems). Could you try a couple of other methods to see if it really isn't available:
- `xrandr --verbose` (there should be a line with EDID_DATA followed by some hex data)
- `get-edid | parse-edid >parsed-edid.out 2>parsed-edid.err`
- `get-edid | hd`
(you will need the read-edid package for the programs get-edid and parse-edid)

[MichalM (jafa81)]

Hi, here is the output....

- `xrandr --verbose` :
===============
Screen 0: minimum 640 x 480, current 800 x 600, maximum 800 x 600
default connected 800x600+0+0 (0xc2) normal (normal) 0mm x 0mm
 Identifier: 0xc1
 Timestamp: 65113
 Subpixel: unknown
 Clones:
 CRTC: 0
 CRTCs: 0
 Panning: 0x0+0+0
 Tracking: 0x0+0+0
 Border: 0/0/0/0
 Transform: 1.000000 0.000000 0.000000
             0.000000 1.000000 0.000000
             0.000000 0.000000 1.000000
            filter:
  800x600 (0xc2) 29.3MHz *current
        h: width 800 start 0 end 0 total 800 skew 0 clock 36.6KHz
        v: height 600 start 0 end 0 total 600 clock 61.0Hz
  640x480 (0xc3) 18.4MHz
        h: width 640 start 0 end 0 total 640 skew 0 clock 28.8KHz
        v: height 480 start 0 end 0 total 480 clock 60.0Hz

- `get-edid | parse-edid >parsed-edid.out 2>parsed-edid.err`:
===========================================
stdout:
=====
root@ubuntu:~# get-edid | parse-edid >parsed-edid.out 2>parsed-edid.err
get-edid: get-edid version 1.4.1

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
 Function supported
 Call successful

 VBE version 300
 VBE string at 0x11110 "Intel(r)915GM/910ML/915MS Graphics Chip Accelerated VGA BIOS"

VBE/DDC service about to be called
 Report DDC capabilities

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
 Function supported
 Call successful

 Monitor and video card combination does not support DDC1 transfers
 Monitor and video card combination does not support DDC2 transfers
 0 seconds per 128 byte EDID block transfer
 Screen is not blanked during DDC transfer

Reading next EDID block

VBE/DDC service about to be called
 Read EDID

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
 Function supported
 Call failed

The EDID data should not be trusted as the VBE call failed
Error: output block unchanged

cat parsed-edid.out:
==============
<empty file>

cat parsed-edid.err:
==============
parse-edid: parse-edid version 1.4.1
parse-edid: IO error reading EDID

- `get-edid | hd`:
============
get-edid: get-edid version 1.4.1

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
 Function supported
 Call successful

 VBE version 300
 VBE string at 0x11110 "Intel(r)915GM/910ML/915MS Graphics Chip Accelerated VGA BIOS"

VBE/DDC service about to be called
 Report DDC capabilities

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
 Function supported
 Call successful

 Monitor and video card combination does not support DDC1 transfers
 Monitor and video card combination does not support DDC2 transfers
 0 seconds per 128 byte EDID block transfer
 Screen is not blanked during DDC transfer

Reading next EDID block

VBE/DDC service about to be called
 Read EDID

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
 Function supported
 Call failed

The EDID data should not be trusted as the VBE call failed
Error: output block unchanged

[Geir Ove Myhr (gomyhr)]

Thank you MichaL. This definitely tells us that the problem is that xorg can't read the EDID information.

Do you still have a working copy of Hardy around? If you don't have it installed, you may download a LiveCD and try it. Hardy has two drivers that would work with this card, the older i810 and the newer intel. You can switch between the two by adding
  Driver "intel"
or
  Driver "i810"
in the Device section of xorg.conf (I'm not sure which one is the default).

The i810 driver is discontinued and therefore not available in newer ubuntu versions. It would be great to know if both drivers work in Hardy or only the i810. If the intel driver works, I would like you to also add
 Option "ModeDebug" "true"
to the Device section of your xorg.conf and upload the log file /var/log/Xorg.0.log and the same EDID related information as you just did for jaunty. Actually, if it only works with i810, it may be useful to have that information in that case as well.

[MichalM (jafa81)]

Hi,
Sure i have hardy installed. This is the last Ubuntu which works with my laptop :-)

I did all tests you asked for. Hardy use intel driver by default. When changed to i810 the resolution went down to 1024x768.

Anyway, find the attached archive that includes following files:
Xorg.0.log_drv_i810
Xorg.0.log_drv_intel

(stdout)
xorg_i810.txt
xorg_intel.txt

(redirected output from read-edid )
i810_parsed-edid.err
i810_parsed-edid.out
intel_parsed-edid.err
intel_parsed-edid.out

Let me know if you need anything else...

[Geir Ove Myhr (gomyhr)]

Hi MichaL,
I've included the files from your tgz-file here, so that they are
easier to access and link to.

It seems that the problem is definitely that the computer is not able
to retrieve any EDID information from the monitor. The files from
Hardy shows that this is the case there as well, so xorg has to guess
what resolution to use. Incidentally, it guesses correctly in Hardy
and not later.

While the problem really lies in the hardware, it is sometimes
possible to work around it. I found a master bug report for cases when
EDID information is not available at bug 194760. Read the description
and post the information it asks for in a comment (and mention this
bug 333644). I'll set this as a duplicate to that.

If you want to troubleshoot more yourself, there is a package called
i2c-tools, that contains some programs to play with I2C-buses (the
EDID information in the monitor is transferred over an I2C bus,
seehttp://en.wikipedia.org/wiki/Display_Data_Channel for more on the
technical details). There is a program called i2cdetect that should be
able to detect buses, but I have never used it and don't know any more
details. Most likely, though, your monitor simply has no EDID
information, which happens every now and then but not very often.