Bug 23112 - [915GM] 'xrandr' with VGA plugged in garbles screen, fifo underrun
Summary: [915GM] 'xrandr' with VGA plugged in garbles screen, fifo underrun
Status: RESOLVED WORKSFORME
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: 7.4 (2008.09)
Hardware: All Linux (All)
: medium major
Assignee: ykzhao
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords: NEEDINFO
: 23429 (view as bug list)
Depends on:
Blocks:
 
Reported: 2009-08-03 08:39 UTC by Bryce Harrington
Modified: 2010-04-12 01:21 UTC (History)
4 users (show)

See Also:
i915 platform:
i915 features:


Attachments
screen-photo.jpg (629.24 KB, image/jpeg)
2009-08-03 08:44 UTC, Bryce Harrington
no flags Details
xrandr.out (581 bytes, text/plain)
2009-08-03 08:45 UTC, Bryce Harrington
no flags Details
CurrentDmesg.txt (5.85 KB, text/plain)
2009-08-03 09:49 UTC, Bryce Harrington
no flags Details
XorgLog.txt (70.81 KB, text/plain)
2009-08-03 09:50 UTC, Bryce Harrington
no flags Details
Output from intel_reg_dumper after steps 1, 2, 3 (9.05 KB, application/octet-stream)
2009-08-19 22:34 UTC, Dag Asheim
no flags Details
bad (9.05 KB, text/plain)
2009-08-19 22:37 UTC, Dag Asheim
no flags Details
good (9.02 KB, text/plain)
2009-08-19 22:38 UTC, Dag Asheim
no flags Details
no-external-display (8.98 KB, text/plain)
2009-08-26 04:56 UTC, Dag Asheim
no flags Details
external-screen-photo.jpg (424.08 KB, image/jpeg)
2009-08-26 13:50 UTC, Dag Asheim
no flags Details
Xorg.log-ModeDebug-KMS (84.98 KB, text/plain)
2009-08-26 13:57 UTC, Dag Asheim
no flags Details
Xorg.log-ModeDebug-UMS (107.68 KB, text/plain)
2009-08-26 13:57 UTC, Dag Asheim
no flags Details
vbios.dump (64.00 KB, application/octet-stream)
2009-08-26 13:58 UTC, Dag Asheim
no flags Details
Dell_2001FP_edid.bin (128 bytes, application/octet-stream)
2009-08-26 15:16 UTC, Dag Asheim
no flags Details
clear it when the underflow occurs after changing mode (824 bytes, patch)
2009-08-26 22:42 UTC, ykzhao
no flags Details | Splinter Review

Description Bryce Harrington 2009-08-03 08:39:26 UTC
Forwarding this bug from Ubuntu reporter Dag Asheim:
https://bugs.edge.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/408432

[Problem]
Running 'xrandr' with no args gives blank screen with some pixel corruption (see photo).

[Original Report]
This is on a Dell Latitide X1 laptop, and only occurs under the following circumstances:

1. xorg is started
2. The external monitor (a Dell 2001 FP) is plugged into the VGA port
3. 'xrandr' is called without arguments, and instantly the screen is garbled - mostly black, except for a few pixels at the top of the screen that appears relatively normal.

If step 2 is done before step 1, the screen stays normal.

The bug is a regression, as earlier (Jaunty and earlier) didn't display this behavior.

ProblemType: Bug
Architecture: i386
Date: Mon Aug 3 16:41:26 2009
DistroRelease: Ubuntu 9.10
MachineType: Dell Inc. Latitude X1
Package: xserver-xorg-video-intel 2:2.8.0-0ubuntu1
ProcCmdLine: root=UUID=513087c1-ebbd-4d02-bc2e-0dbc1cc68719 ro quiet splash
ProcEnviron:
 LANGUAGE=nb_NO.UTF-8
 LANG=nb_NO.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-4.23-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.5-1ubuntu1
 libdrm2 2.4.12-1ubuntu1
 xserver-xorg-video-intel 2:2.8.0-0ubuntu1
 xserver-xorg-video-ati 1:6.12.99+git20090629.f39cafc5-0ubuntu4
SourcePackage: xserver-xorg-video-intel
Uname: Linux 2.6.31-4-generic i686
dmi.bios.date: 06/21/2005
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A03
dmi.board.name: 0G6951
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA03:bd06/21/2005:svnDellInc.:pnLatitudeX1:pvr:rvnDellInc.:rn0G6951:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude X1
dmi.sys.vendor: Dell Inc.
fglrx: Not loaded
system:
 distro: Ubuntu
 architecture: i686kernel: 2.6.31-4-generic
Comment 1 Bryce Harrington 2009-08-03 08:44:50 UTC
Created attachment 28307 [details]
screen-photo.jpg
Comment 2 Bryce Harrington 2009-08-03 08:45:24 UTC
Created attachment 28308 [details]
xrandr.out
Comment 3 Bryce Harrington 2009-08-03 09:49:53 UTC
Created attachment 28309 [details]
CurrentDmesg.txt
Comment 4 Bryce Harrington 2009-08-03 09:50:34 UTC
Created attachment 28310 [details]
XorgLog.txt
Comment 5 Wang Zhenyu 2009-08-11 18:59:17 UTC
Does this laptop has real TV output? What's the last kernel that works?
Comment 6 Dag Asheim 2009-08-12 06:51:15 UTC
The laptop does not have any TV ports.

The last environment that works OK for me, is Ubuntu 9.04 (Jaunty) which according to 'uname -r' runs Linux version 2.6.27-14-generic. I tried some early Karmic alphas, but then X didn't work at all (even before issuing a 'xrandr' command).

Do you think that the problem is primarily with the kernel, and not with X?
Comment 7 Michael Fu 2009-08-17 18:28:10 UTC
>1. xorg is started
>2. The external monitor (a Dell 2001 FP) is plugged into the VGA port
>3. 'xrandr' is called without arguments, and instantly the screen is garbled -
>mostly black, except for a few pixels at the top of the screen that appears
>relatively normal.
>
>If step 2 is done before step 1, the screen stays normal.

looks like there is no EDID at all for VGA after monitor plugged in.


Comment 8 ykzhao 2009-08-17 20:56:05 UTC
Agree with what Michael said in comment #7. It seems that there is no EDID for the VGA monitor.
     Does this issue still exist when using another external monitor?
    Will you please add the modedebug option in xorg.conf and attach the xorg.log? Can it work well under UMS mode? Please attach the xorg.log under UMS mode. 
    Will you please also attach the vbios.dump? You can use the following command to get the vbios.dump
    echo 1 > /sys/devices/pci0000:00/0000:00:02.0/rom
    cat /sys/devices/pci0000:00/0000:00:02.0/rom >vbios.dump
    echo 0 > /sys/devices/pci0000:00/0000:00:02.0/rom

Thanks.
Comment 9 Michael Fu 2009-08-19 06:26:03 UTC
a comparison intel_reg_dump output of good and bad case will also provide good hints. it's in xserver-xorg-video-intel-dbg package in Ubuntu.

>1. xorg is started
>2. The external monitor (a Dell 2001 FP) is plugged into the VGA port
>3. 'xrandr' is called without arguments, and instantly the screen is garbled -
>mostly black, except for a few pixels at the top of the screen that appears
>relatively normal.

please capture a reg snapshot via running intel_reg_dump, name it as bad

>If step 2 is done before step 1, the screen stays normal.

and in this environment, run intel_reg_dump again, name it as good.

please then attach both output here. thanks.


Comment 10 Dag Asheim 2009-08-19 22:34:50 UTC
Created attachment 28806 [details]
Output from intel_reg_dumper after steps 1, 2, 3
Comment 11 Dag Asheim 2009-08-19 22:37:15 UTC
Created attachment 28807 [details]
bad
Comment 12 Dag Asheim 2009-08-19 22:38:43 UTC
Created attachment 28808 [details]
good
Comment 13 Dag Asheim 2009-08-19 23:05:13 UTC
I noticed some lines in /var/log/syslog that might be relevant. They don't seem to be consistently reproducible, but still...

Aug 20 07:18:05 dash-laptop kernel: [78019.257267] integrated sync not supported
Aug 20 07:18:05 dash-laptop kernel: [78019.467472] [drm] DAC-6: set mode  25
Aug 20 07:18:08 dash-laptop kernel: [78022.745272] render error detected, EIR: 0x00000010
Aug 20 07:18:08 dash-laptop kernel: [78022.745279] page table error
Aug 20 07:18:08 dash-laptop kernel: [78022.745281]   PGTBL_ER: 0x00000100
Aug 20 07:18:08 dash-laptop kernel: [78022.745287] [drm:i915_handle_error] *ERROR* EIR stuck: 0x00000010, masking
Aug 20 07:18:08 dash-laptop kernel: [78022.745298] render error detected, EIR: 0x00000010
Aug 20 07:18:08 dash-laptop kernel: [78022.745301] page table error
Aug 20 07:18:08 dash-laptop kernel: [78022.745303]   PGTBL_ER: 0x00000100
Comment 14 Gordon Jin 2009-08-25 18:10:15 UTC
*** Bug 23429 has been marked as a duplicate of this bug. ***
Comment 15 Michael Fu 2009-08-25 20:04:07 UTC
would you please attach a regdump without any external display attached?  thanks.
Comment 16 Dag Asheim 2009-08-26 04:56:31 UTC
Created attachment 28915 [details]
no-external-display
Comment 17 Michael Fu 2009-08-26 06:27:40 UTC
btw, you only attached a screenshot of the garbled screen on the laptop panel, how about the VGA monitor? Is it ok when the laptop panel is garbled? thanks.
Comment 18 Michael Fu 2009-08-26 06:41:14 UTC
(In reply to comment #8)
> Agree with what Michael said in comment #7. It seems that there is no EDID for
> the VGA monitor.
>      Does this issue still exist when using another external monitor?
>     Will you please add the modedebug option in xorg.conf and attach the
> xorg.log? Can it work well under UMS mode? Please attach the xorg.log under UMS
> mode. 
>     Will you please also attach the vbios.dump? You can use the following
> command to get the vbios.dump
>     echo 1 > /sys/devices/pci0000:00/0000:00:02.0/rom
>     cat /sys/devices/pci0000:00/0000:00:02.0/rom >vbios.dump
>     echo 0 > /sys/devices/pci0000:00/0000:00:02.0/rom
> 
> Thanks.
> 

Dag, yakui's request in comment# 17 is also helpful for root-cause the bug. please kindly follow up to provide the logs.

fyi, when you need to use UMS mode, add i915.modeset=0 to kernel boot parameters.

thanks.
Comment 19 Dag Asheim 2009-08-26 13:31:57 UTC
The external monitor is also garbled. I'll attach a photo. The dots in the middle of the screen seems to be a weird rendering of the mouse cursor, as it moves along with the mouse.

I only answered yakui's request at the Ubuntu bug tracker, where I saw it first. Sorry for the confusion I caused for not keeping the two bug trackers in sync, I'll make amends and upload the files here as well.

The gist of it is that I can't reproduce the bug under UMS (booting with i915.modeset=0), so it is probably KMS related.
Comment 20 Dag Asheim 2009-08-26 13:50:38 UTC
Created attachment 28936 [details]
external-screen-photo.jpg
Comment 21 Dag Asheim 2009-08-26 13:57:17 UTC
Created attachment 28937 [details]
Xorg.log-ModeDebug-KMS
Comment 22 Dag Asheim 2009-08-26 13:57:54 UTC
Created attachment 28938 [details]
Xorg.log-ModeDebug-UMS
Comment 23 Dag Asheim 2009-08-26 13:58:16 UTC
Created attachment 28939 [details]
vbios.dump
Comment 24 Dag Asheim 2009-08-26 15:15:37 UTC
Btw, I see that the title of the report is modified with an "VGA (without EDID)". I'll just mention that the Dell 2001 FP normally reports EDID info just fine, so any missing EDID info is probably the fault of X or the kernel. I'll attach a copy of the EDID info acquired via the nvidia-settings tool (from another computer using the DVI connection), in case that is of any help.
Comment 25 Dag Asheim 2009-08-26 15:16:45 UTC
Created attachment 28940 [details]
Dell_2001FP_edid.bin
Comment 26 ykzhao 2009-08-26 22:42:40 UTC
Created attachment 28942 [details] [review]
clear it when the underflow occurs after changing mode

Will you please try the debug patch on the latest kernel(2.6.31-rc7) and see whether the issue still exists?
Thanks.
Comment 27 ykzhao 2009-08-26 23:01:23 UTC
Hi, Dag
    From the log in comment #21 it seems that the EDID can also be obtained for VGA monitor. 
    But from the register dump in comment #11/12 it seems that the register of PIPEASTAT is different.
    -(II):             PIPEASRC: 0x031f0257 (800, 600)
-(II):            PIPEASTAT: 0x00000303 (status: VSYNC_INT_STATUS DLINE_COMPARE_STATUS VBLANK_INT_STATUS OREG_UPDATE_STATUS)
+(II):             PIPEASRC: 0x063f04af (1600, 1200)
+(II):            PIPEASTAT: 0x80000303 (status: FIFO_UNDERRUN VSYNC_INT_STATUS DLINE_COMPARE_STATUS VBLANK_INT_STATUS OREG_UPDATE_STATUS)

     I am not sure whether the issue is related with the PIPEA underflow.
   Will you please try the debug patch in comment #26 on the latest kernel(2.6.31-rc7) and see whether the issue still exists?
  
When the problem happens, please switch to other resolution and see whether the problem still exits. For example: 1280x1024, 1024x768.
  
Thanks.
Comment 28 ykzhao 2009-08-27 03:25:13 UTC
Will you please try to set the following modes for VGA/LVDS under UMS mode and see whether it still works well?
   LVDS: 1024x768
   VGA: 1600x1200

After the test, please attach the register dump and Xorg.log.
Thanks.
Comment 29 Dag Asheim 2009-08-31 02:39:28 UTC
I have been sidetracked by some other problems (my wireless router died, and
an upgrade to karmic had some unwanted side effects), so I haven't been able
to test this thoroughly yet. But I have compiled a new kernel with the patch,
and the obvious effect is that the screen goes black when I issue the 'xrandr'
command. More details and log files will follow.
Comment 30 Michael Fu 2009-09-02 18:02:18 UTC
(In reply to comment #29)
> I have been sidetracked by some other problems (my wireless router died, and
> an upgrade to karmic had some unwanted side effects), so I haven't been able
> to test this thoroughly yet. But I have compiled a new kernel with the patch,
> and the obvious effect is that the screen goes black when I issue the 'xrandr'
> command. More details and log files will follow.
> 

logs? Dag?
Comment 31 Michael Fu 2009-09-02 18:10:12 UTC
please try this patch as well: http://bugs.freedesktop.org/show_bug.cgi?id=22921#c5, _without_ patch in comment# 26.
Comment 32 Michael Fu 2009-09-10 00:32:44 UTC
ping~ Dag.
Comment 33 Michael Fu 2009-09-28 19:57:29 UTC
ping~ dag...
Comment 34 Michael Fu 2009-12-25 20:04:23 UTC
ping Dag...
Comment 35 Geir Ove Myhr 2010-01-24 12:41:26 UTC
Another user (fiacobelli) who says he has the same problem has tested the kernel 2.6.31-rc7, both without any patches and with each of the patches in comments #26 and #31 without making it better. What information are you interested in at this time? I suppose it is best if he files a separate bug report?
Comment 36 ykzhao 2010-01-30 03:36:56 UTC
Can you try the following patch set on 2.6.33-rc5 kernel and see whether
the issue still exists?
    >http://lists.freedesktop.org/archives/intel-gfx/2010-January/005505.html

BTW: the patch 1 can be skipped as it is already shipped in 2.6.33-rc5 kernel.

Thanks.
   Yakui
Comment 37 Gordon Jin 2010-04-12 01:21:29 UTC
Closing as losing communications with the reporter.

Geir, you could ask fiacobelli to file a separate bug. Thanks.


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