Bug 26199 - kernel oops in 2.6.33 rc5 when dri is set to off in xorg.conf
Summary: kernel oops in 2.6.33 rc5 when dri is set to off in xorg.conf
Status: RESOLVED INVALID
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Radeon (show other bugs)
Version: XOrg git
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: Default DRI bug account
QA Contact:
URL:
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Depends on:
Blocks:
 
Reported: 2010-01-24 12:17 UTC by Peter Hercek
Modified: 2010-01-30 06:24 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
dmesg with dri off and booting to X (33.62 KB, text/plain)
2010-01-24 12:17 UTC, Peter Hercek
no flags Details
dmesg when I booted to console only (32.38 KB, text/plain)
2010-01-24 12:18 UTC, Peter Hercek
no flags Details
xorg.conf when the error happend (2.12 KB, text/plain)
2010-01-25 13:42 UTC, Peter Hercek
no flags Details
Xorg.log (not when the eroror happend, everything the same except kernel) (43.35 KB, text/plain)
2010-01-25 13:47 UTC, Peter Hercek
no flags Details

Description Peter Hercek 2010-01-24 12:17:00 UTC
Created attachment 32797 [details]
dmesg with dri off and booting to X

If option dri is set to off and I'm booting to X then I get the oops. When it is set to on (or I boot only to console) I do not get the oops. Still the acceleration is not working when dri is set to on. It complains about dri version mismatch which is strange since I compiled libdrm with --enable-radeon-experimental-api and I recompiled xf86-video-ati and mesa only after the new libdrm was installed. But this is probably a separate issue. Anyway looks to me it should not be possible to make kernel oops so here is the report. Ach, and it is an agp system but I never had any stability problems with it on windows (also worked very well with 2.6.30 and agd5f's r6xx-r7xx-3d drm module with agp 8x and even the fast writes).

I'll attach dmesg with the oops and also without it (a boot to console).
Comment 1 Peter Hercek 2010-01-24 12:18:25 UTC
Created attachment 32798 [details]
dmesg when I booted to console only
Comment 2 Alex Deucher 2010-01-25 08:00:17 UTC
Please attach your xorg log and config.
Comment 3 Peter Hercek 2010-01-25 13:41:38 UTC
I cannot simulate the bug as it was when I reported the error. I'll attach the exact xorg.conf I used, but I do not have Xorg.0.log any more. But I looked at it when the errors happened and there were not any errors or warnings which are not in the Xorg.0.log I'll attach. But the log I'll attach is when I booted 2.6.32.
I thought the error is repeatable since I tried 2 times and it happened 2 times. But I do not think so any more. It is not a problem to crash it again, but this time the machine is completely locked up, not even ssh works. Computer does not seem to react to keyboard too (keyboard leds do work though).
When I set radeon.agpmode=-1 on the kernel command line I'm not able to make the kernel crash. I tried 6 times. Without setting agpmode to -1 it crashes with probability of about 0.5 when DRI is off. When DRI is on it typically does not crash.
So it looks like it is related to AGP. I did not have any AGP related problems in linux before nor I have them in windows now.
Comment 4 Peter Hercek 2010-01-25 13:42:26 UTC
Created attachment 32812 [details]
xorg.conf when the error happend
Comment 5 Peter Hercek 2010-01-25 13:47:29 UTC
Created attachment 32813 [details]
Xorg.log (not when the eroror happend, everything the same except kernel)

Notice that when the error happened as I described it the first time the machine did boot to X at the end and was usable (without dri with sw renderer). Not sure whether X server was restarted though. My guess would be that not but I did not check it.
Comment 6 Michel Dänzer 2010-01-26 02:02:52 UTC
(In reply to comment #3)
> When I set radeon.agpmode=-1 on the kernel command line I'm not able to make
> the kernel crash. I tried 6 times. Without setting agpmode to -1 it crashes
> with probability of about 0.5 when DRI is off. When DRI is on it typically does
> not crash.

radeon.agpmode only has an effect if KMS is enabled, in which case an X driver with KMS support can't really work without the DRI; not sure what happens if you try. But from

> It complains about dri version mismatch which is strange since I compiled
> libdrm with --enable-radeon-experimental-api [...]

it sounds like your X driver doesn't have KMS support built in, in which case it's not expected to work properly at all if KMS is enabled.

In summary, unless your X log contains a line like

(II) [KMS] Kernel modesetting enabled.

without Option "DRI" "off", this report is probably invalid.
Comment 7 Peter Hercek 2010-01-26 03:35:05 UTC
(In reply to comment #6)
> In summary, unless your X log contains a line like
> 
> (II) [KMS] Kernel modesetting enabled.
> 
> without Option "DRI" "off", this report is probably invalid.

Ok, so this report is invalid since when I run without radeon.agpmode=-1 and when Option DRI is on then I do not have line

(II) [KMS] Kernel modesetting enabled.

in my Xorg.log.
Comment 8 Peter Hercek 2010-01-26 06:44:20 UTC
I had incorrectly (with --disable-kms) compiled xf86-video-ati. I recompiled everything (libdrm, mesa, xf86-xf86-video-ati) today from git master and it seems to work ... well until I try to put "video=1280x1024" on kernel command line. Then I get another hard kernel crash and lockup. But that is probably something completely different. Should I create a bug report for it?

Btw it looks like Bug 18397 (Small pixmap corruption [EXA enabled]) is not there any more with kernel mode setting enabled.


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