2.6.35-6.9 (and newer) kernels having issues with invalid EDID info and ATI Radeon graphics

[sam tygier]

The real reason that this only happens with newer kernels is that before:
commit 61e57a8d72f2336faf39b5d940215cf085e01e6e
Author: Adam Jackson <ajax <at> redhat.com>
Date: Mon Mar 29 21:43:18 2010 +0000
 drm/edid: Fix secondary block fetch.
which reached mainline in 2.6.35, only the base block of the EDID was read. Now the extension blocks are also being read. If any of the extension blocks are invalid then the whole EDID is thrown away.

the new patch only throws away the bad extension.

there is an upstream bug at https://bugs.freedesktop.org/show_bug.cgi?id=31154

== second description ==

The kernel has become fussy about EDID information from the monitor. When using kernel mode setting (KMS) the kernel will refuse to setup a monitor with invalid EDID (even if those which worked with previous kernels).

Radeon still has user mode setting, which seems to bypass the EDID strictness. so to boot one can append the following to the grub kernel line:

radeon.modeset=0

== original description ==

i install maverick with todays live cd. after install there was a lot of updates available (including xorg and kernel). after these updates i can't boot. i get a stuck at a blank screen after grub. i can't switch VT. same happens even with recovery mode.

if i select the old kernel 2.6.34-5.14 at grub i can boot fine.

i tried to use "ubuntu-bug linux" to report the issue, but i says "This is not a genuine Ubuntu package" i guess this is because i am booted with an old kernel. so please let me know what info you might need. i'll attach syslog, because that defiantly has some interesting messages. there is a failed boot starting at Jul 3 14:32:00
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
AplayDevices: aplay: device_list:235: no soundcards found...
Architecture: amd64
ArecordDevices: arecord: device_list:235: no soundcards found...
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/controlC1', '/dev/snd/hwC1D0', '/dev/snd/pcmC1D3p', '/dev/snd/by-path', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/pcmC0D1c', '/dev/snd/pcmC0D1p', '/dev/snd/pcmC0D2c', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CRDA: Error: [Errno 2] No such file or directory
DistroRelease: Ubuntu 10.10
HibernationDevice: RESUME=UUID=39a09ba5-66d6-431f-94fc-b6b8c5550a28
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Alpha amd64 (20100605)
Package: linux (not installed)
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-7-generic root=UUID=46ef5009-4985-4715-9265-5851f8956be8 ro quiet splash
ProcEnviron:
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.35-7.12-generic 2.6.35-rc4
Regression: Yes
RelatedPackageVersions: linux-firmware 1.37
Reproducible: Yes
RfKill:

Tags: maverick graphics regression-potential needs-upstream-testing
Uname: Linux 2.6.35-7-generic x86_64
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
dmi.bios.date: 11/07/2007
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: 6.00
dmi.board.name: S2696
dmi.board.vendor: Tyan Computer Corporation
dmi.chassis.type: 6
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvr6.00:bd11/07/2007:svn:pn:pvr:rvnTyanComputerCorporation:rnS2696:rvr:cvn:ct6:cvr:

[sam tygier (samtygier)]

apport information

[sam tygier (samtygier)]

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[sam tygier (samtygier)]

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[sam tygier (samtygier)]

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[sam tygier (samtygier)]

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[sam tygier (samtygier)]

some more detail:
while the computer is hung at the blank screen i can log in over ssh. the machine is running, it just wont display to the monitor or switch to a VT. so i was able to use apport-collect.
it still happens with 2.6.35-7-generic

[sam tygier (samtygier)]

with radeon.modset=0 i can boot fine

[sam tygier (samtygier)]

still an issue with 2.6.35-15-generic

[sam tygier (samtygier)]

similar error message in Bug #539851 maybe its related

[sam tygier (samtygier)]

just to note i think the interesting part of the above logs in this:

Jul 3 14:32:04 oberon kernel: [ 13.221469] [drm:drm_edid_block_valid] *ERROR* Raw EDID:
Jul 3 14:32:04 oberon kernel: [ 13.221512] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221514] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221517] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221519] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221521] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221523] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221525] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221527] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.221529]
Jul 3 14:32:04 oberon kernel: [ 13.272318] [drm:drm_edid_block_valid] *ERROR* Raw EDID:
Jul 3 14:32:04 oberon kernel: [ 13.272351] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272353] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272355] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272357] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272360] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272362] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272364] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272366] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:04 oberon kernel: [ 13.272368]
Jul 3 14:32:05 oberon kernel: [ 13.323123] [drm:drm_edid_block_valid] *ERROR* Raw EDID:
Jul 3 14:32:05 oberon kernel: [ 13.323159] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323161] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323164] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323166] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323168] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323170] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323172] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul 3 14:32:05 oberon kernel: [ 13.323175] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Jul...

[sam tygier (samtygier)]

maybe this is useful. monitor is a EIZO S2242W

sam@oberon:~$ xrandr --prop
Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 1920 x 1920
HDMI-0 disconnected (normal left inverted right x axis y axis)
 scaler: off
 coherent_mode: 1 (0x00000001) range: (0,1)
VGA-0 disconnected (normal left inverted right x axis y axis)
 load_detection: 1 (0x00000001) range: (0,1)
DVI-0 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 474mm x 297mm
 EDID:
  00ffffffffffff0015c3042001010101
  1113010380301e78eaf5c5a85337ae25
  125054a10800a94081808140b3000101
  010101010101283c80a070b023403020
  3600da291100001a000000ff00323530
  32363034390a20202020000000fd003b
  3d1f4c11000a202020202020000000fc
  005332323432570a2020202020200154
  00000000000000000000000000000000
  00000000000000000000000000000000
  00000000000000000000000000000000
  00000000000000000000000000000000
  00000000000000000000000000000000
  00000000000000000000000000000000
  00000000000000000000000000000000
  00000000000000000000000000000000
 dvi_monitor_type: auto
 scaler: off
 coherent_mode: 1 (0x00000001) range: (0,1)
 load_detection: 1 (0x00000001) range: (0,1)
   1920x1200 60.0*+
   1600x1200 60.0
   1680x1050 59.9
   1280x1024 60.0
   1280x960 60.0
   1024x768 60.0
   800x600 60.3
   640x480 59.9
   720x400 70.1

[sam tygier (samtygier)]

this is a regression that prevents booting. i think that makes it a high.

also, i checked with 2.6.36rc3 from the mainline ppa. same problem.

[sam tygier (samtygier)]

another similar one Bug #598322

[Robbie Williamson (robbiew)]

Using the radeon.modset=0 workaround, are you able to boot and have the graphics setup that you require? That is, does setting that to 0 break anything else for you?

[sam tygier (samtygier)]

with user mode setting it boots and finds the resolution fine. but i loose the fast mode switching and if i have 2 users logged in the second has very slow desktop due to no graphics acceleration.

I have also tested with a different monitor, a Dell 2209WA. that boots fine with the default settings, and can accelerate multiple logged in users. do you want any log files from the dell?

[Robbie Williamson (robbiew)]

Given there is a workaround and it seems monitor specific, setting to Medium. However, since it is a regression we should still try to fix.

[Robbie Williamson (robbiew)]

Could you please verify this bug still exists in our latest kernel -> 2.6.35-22.32? We are about to rollout a newer kernel (see https://bugs.launchpad.net/bugs/641618), but I don't believe the fixes there address this.

[Magnus Kulke (magnus-kulke)]

i think this affects me aswell. i am using an lenovo s10-3 netbook (which has pretty much a stock netbook configuration), which i updated from lucid to maverick (i386). The only 2.6.35 kernel which is working, is 2.6.35-020635rc1-generic for lucid from the mainline ppa. when i boot e.g. 2.6.35-22-generic i get stuck with a black screen and a blinking prompt. i did download the daily maverick livecd and there was the same behaviour when trying to boot from it. when i boot without "quiet splash" from the livecd i can see it stalls after the message "[drm] initialized drm 1.1.0 20060810". nomodeset does not seem to help either. i tried the lates 2.6.36rc kernels from the mainline ppa for maverick, but it was the same with those kernels.

specs from my netbook:

lscpi:

00:00.0 Host bridge: Intel Corporation N10 Family DMI Bridge
00:02.0 VGA compatible controller: Intel Corporation N10 Family Integrated Graphics Controller
00:02.1 Display controller: Intel Corporation N10 Family Integrated Graphics Controller
00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 1 (rev 02)
00:1c.2 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 3 (rev 02)
00:1d.0 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 (rev 02)
00:1d.3 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 (rev 02)
00:1d.7 USB Controller: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e2)
00:1f.0 ISA bridge: Intel Corporation NM10 Family LPC Controller (rev 02)
00:1f.2 SATA controller: Intel Corporation N10/ICH7 Family SATA AHCI Controller (rev 02)
00:1f.3 SMBus: Intel Corporation N10/ICH 7 Family SMBus Controller (rev 02)
05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02)
09:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

lsusb

Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 0489:e00d Foxconn / Hon Hai
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 15ca:00c3 Textech International Ltd. Mini Optical Mouse
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 006: ID 090c:c37b Feiya Technology Corp.
Bus 001 Device 005: ID 0bda:0158 Realtek Semiconductor Corp. USB 2.0 multicard reader
Bus 001 Device 002: ID 13fd:2040 Initio Corporation
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

cat /proc/cpuinfo

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 28
model name : Intel(R) Atom(TM) CPU N450 @ 1.66GHz
stepping : 10
cpu MHz : 1000.000
cache size : 512 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 0
init...

[Magnus Kulke (magnus-kulke)]

i tried a few more kernels from mainline ppa and found out that up to 2.6.35.3-maverick (2.6.35-02063503-generic) the system boots up. 2.6.35.4-maverick (2.6.35-02063504-generic) and more recent kernels won't boot. in the changelog were some drm/intel specific commits, maybe those have sth to do with the problem.

[sam tygier (samtygier)]

still have the issue with 2.6.35-22-generic

[Robbie Williamson (robbiew)]

Magnus, please open a separate bug (subscribeme, robbie.w) as you have an Intel graphics card and the reporter of this bug has using the radeon driver.

[sam tygier (samtygier)]

i think i understand the issue now. my main EDID block claims to have an extension block. but the extension block is invalid. i have a messy patch to revert back to the main block if there is a an invalid extension. i shall clean it up and submit it.

[sam tygier (samtygier)]

here is a patch against the ubuntu maverick kernel.

the change is in a code path only taken in the failing case, so it should not effect any currently working setup.

[sam tygier (samtygier)]

I had some feed back from ajax ondri-devel
http://thread.gmane.org/gmane.comp.video.dri.devel/50127

i shall make a second version of this patch.

[baben (herr-lefrog)]

It seems to be the same problem here.

Kernel: 2.6.35-22
Dell Latitude E6410 ATG
Graphics card: Mobile Intel Integrated Graphics Media Accelerator X4500HD

after grub I get a blank screen on every boot.
when I plug in an external monitor I get a signal only at the external screen.
if I unplug the external monitor I get a blank screen.
if I then plug in the external monitor again I get a signal on both screens.

I've tried:
Samsung SyncMaster LD190
DELL TFT Monitor 2209WA

same issue.

[sam tygier (samtygier)]

if you pull this please take the patch from:
http://thread.gmane.org/gmane.comp.video.dri.devel/50127

it will keep good extensions if there are good and bad ones.

[sam tygier (samtygier)]

oops. this link should be better
http://article.gmane.org/gmane.comp.video.dri.devel/50176

[nutznboltz (nutznboltz-deactivatedaccount)]

Same problem with

01:00.0 VGA compatible controller [0300]: nVidia Corporation GT218 [GeForce 210] [10de:0a65] (rev a2)

Monitor: DS-275W

Raw EDID bytes:

  00 ff ff ff ff ff ff 00 1a 36 fa 00 00 00 00 00
  1c 13 01 03 a5 3c 22 78 e2 6f b1 a7 55 4c 9e 25
  0c 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01
  01 01 01 01 01 01 56 5e 00 a0 a0 a0 29 50 30 20
  35 00 55 50 21 00 00 1a 00 00 00 fc 00 31 34 34
  30 50 0a 20 20 20 20 20 20 20 00 00 00 fc 00 20
  2d 57 51 58 47 41 0a 20 20 20 20 20 00 00 00 fc
  00 43 6f 6c 6f 72 20 4c 43 44 0a 20 20 20 01 fc
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

# get-edid | parse-edid
parse-edid: parse-edid version 2.0.0
get-edid: get-edid version 2.0.0

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

 VBE version 300
 VBE string at 0x2110 "NVIDIA"

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 supports 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
EDID claims 255 more blocks left
EDID blocks left is wrong.
Your EDID is probably invalid.
parse-edid: EDID checksum failed - data is corrupt. Continuing anyway.
parse-edid: first bytes don't match EDID version 1 header
parse-edid: do not trust output (if any).

 # EDID version 255 revision 255
Section "Monitor"
 Identifier "___:ffff"
 VendorName "___"
 ModelName "___:ffff"
 # DPMS capabilities: Active off:yes Suspend:yes Standby:yes

 Mode "4095x4095" # vfreq 9.770Hz, hfreq 80.018kHz
  DotClock 655.350000
  HTimings 4095 4350 4605 8190
  VTimings 4095 4158 4221 8190
  Flags "Interlace" "+HSync" "+VSync"
 EndMode
 Mode "4095x4095" # vfreq 9.770Hz, hfreq 80.018kHz
  DotClock 655.350000
  HTimings 4095 4350 4605 8190
  VTimings 4095 4158 4221 8190
  Flags "Interlace" "+HSync" "+VSync"
 EndMode
 Mode "4095x4095" # vfreq 9.770Hz, hfreq 80.018kHz
  DotClock 655.350000
  HTimings 4095 4350 4605 8190
  VTimings 4095 4158 4221 8190
  Flags "Interlace" "+HSync" "+VSync"
 EndMode
 Mode "4095x4095" # vfreq 9.770Hz, hfreq 80.018kHz
  DotClock 655.350000
  HTimings 4095 4350 4605 8190
  VTimings 4095 4158 4221 8190
  Flags "Interlace" "+HSync" "+VSync"
 EndMode
EndSection

[sam tygier (samtygier)]

patch has been accepted upstream into 2.6.37
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0ea75e23356f73b4300492e04a62c90787a55c2d

[Leann Ogasawara (leannogasawara)]

Hi Sam,

Looks like this patch has already been pulled into the upcoming Natty kernel. Thus I'm marking the active linux tracking task as Fix Released.

ubuntu-natty$ git describe --contains 0ea75e23356f73b4300492e04a62c90787a55c2d
Ubuntu-2.6.37-7.18~383^2~13

The Maverick linux task still remains open. I'd suggest if we want this to land in Maverick automatically, the best approach would be to get the patch accepted into an upcoming upstream stable 2.6.35.y release. Thanks.

[Axel Mueller (aegges)]

A fix for Maverick would be nice. I am using kernel 2.6.35-26 and still have the problem with my ATI card (RS690).
X behaves jerky and dmesg is spammed with EDID messages (every second or so).

[sam tygier (samtygier)]

@axel
could you attach you dmesg. also which monitor do you have?

[Axel Mueller (aegges)]

dmesg attached

Monitor is Hanns.G JC198DP

[Axel Mueller (aegges)]

And here the output of get-edid:

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

        VBE version 300
        VBE string at 0xc01b8 "ATI ATOMBIOS"

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 supports 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 successful

parse-edid: EDID checksum passed.
axel@zeus:~/Downloads$ more edid

        # EDID version 1 revision 3
Section "Monitor"
        # Block type: 2:0 3:ff
        # Block type: 2:0 3:fd
        # Block type: 2:0 3:fc
        Identifier "JC198D"
        VendorName "HSD"
        ModelName "JC198D"
        # Block type: 2:0 3:ff
        # Block type: 2:0 3:fd
        HorizSync 30-83
        VertRefresh 50-76
        # Max dot clock (video bandwidth) 140 MHz
        # Block type: 2:0 3:fc
        # DPMS capabilities: Active off:yes Suspend:no Standby:no

        Mode "1280x1024" # vfreq 60.020Hz, hfreq 63.981kHz
                DotClock 108.000000
                HTimings 1280 1328 1440 1688
                VTimings 1024 1025 1028 1066
                Flags "+HSync" "+VSync"
        EndMode
        # Block type: 2:0 3:ff
        # Block type: 2:0 3:fd
        # Block type: 2:0 3:fc
EndSection

The monitor is attached to the DVI port. HDMI port is not connected.

[sam tygier (samtygier)]

you dmesg says that block 0 is invalid. my patch on helps if block 0 is good, but an extension block is invalid. you could try a more recent kernel to see if it helps, 2.6.37, or a 2.6.38-rc
http://kernel.ubuntu.com/~kernel-ppa/mainline/

[Axel Mueller (aegges)]

A kernel update to 2.6.38 did not help. There is a problem with my mainboard (Asus M2A-VM). There is no HDMI monitor connected but the kernel still tries to read the EDID. For more info see https://bugzilla.redhat.com/show_bug.cgi?id=668196 and http://ubuntuforums.org/showthread.php?t=1607778

I found three possible solutions to solve my problem:
1) put this kernel parameter into my grub.cfg "radeon.modeset=0"
Unfortunately, the X server will the segfault after some time
2) get the kernel source and patch the radeon driver, see http://ubuntuforums.org/showthread.php?t=1607778
this works, but you have to patch the kernel after every update again
3) execute the command
"echo -n N > /sys/module/drm_kms_helper/parameters/poll"

This will effectively stop the pollution of the dmesg (and all the quirky X behavior). This option does not exist in kernel 2.6.35 that's why I had update to kernel 2.6.38

[nutznboltz (nutznboltz-deactivatedaccount)]

Would it make sense to do some crowd sourcing here? If a test program that identified if a monitor's EDID was broken and report back to a database was distributed before a Linux that requires EDID to work was sent out it might be useful.

[sam tygier (samtygier)]

i think it would be best to start a new bug for your issue. this report and patch is for invalid extension blocks, and has been fixed (in 2.6.37).

you issue is about the kernel demanding EDID for an unconnected monitor.

[Axel Mueller (aegges)]

>i think it would be best to start a new bug for your issue. this report and patch is for invalid extension blocks, and has been fixed (in >2.6.37).
>you issue is about the kernel demanding EDID for an unconnected monitor.
 I opened a new bug #722806
Thanks for your help anyway.

[Julian Wiedmann (jwiedmann)]

This release has reached end-of-life [0].

[0] https://wiki.ubuntu.com/Releases