Bug 35246 - Screen flashes and xorg goes in loop
Summary: Screen flashes and xorg goes in loop
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/Radeon (show other bugs)
Version: 7.6 (2010.12)
Hardware: Other All
: medium normal
Assignee: xf86-video-ati maintainers
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-03-12 04:01 UTC by Diego
Modified: 2011-08-06 03:35 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
Xorg log containing crash and backtrace. (42.75 KB, patch)
2011-03-12 04:01 UTC, Diego
no flags Details | Splinter Review
dmesg (general, not related to the crash) (136.71 KB, text/plain)
2011-03-12 04:03 UTC, Diego
no flags Details
dmesg with AGP 4x working correctly (30.14 KB, text/plain)
2011-08-06 03:35 UTC, Diego
no flags Details

Description Diego 2011-03-12 04:01:47 UTC
Created attachment 44389 [details] [review]
Xorg log containing crash and backtrace.

My card (Radeon HD 3650 AGP 512MB) makes my monitor rapidly flash (black screen for just a moment) with kernel modesetting in 2.6.37 (tried 2.6.38 too).

Moreover, from time to time, especially watching flash videos or using 3D effects, Xorg goes in loop and lock the computer. Only from time to time I'm able to get to VT.

# uname -a
Linux myhost 2.6.37-ARCH #1 SMP PREEMPT Tue Mar 8 08:08:06 UTC 2011 i686 AMD Athlon(TM) XP 1800+ AuthenticAMD GNU/LinuxLinux myhost 2.6.37-ARCH #1 SMP PREEMPT Tue Mar 8 08:08:06 UTC 2011 i686 AMD Athlon(TM) XP 1800+ AuthenticAMD GNU/Linux

# lspci | grep VGA
01:00.0 VGA compatible controller: ATI Technologies Inc RV635 PRO AGP [Radeon HD 3650]

Distro: Arch Linux
Xorg version: 7.6
Xserver version: 1.9.4
Ati video driver version: 6.14
Mesa: 7.10.1 (Gallium)
Comment 1 Diego 2011-03-12 04:03:35 UTC
Created attachment 44390 [details]
dmesg (general, not related to the crash)
Comment 2 Diego 2011-03-12 04:04:22 UTC
Don't know if it's relevant: I use a DVI to VGA adapter to attach my CRT monitor.
Comment 3 Alex Deucher 2011-03-15 00:19:06 UTC
Does booting with radeon.agpmode=-1 on the kernel command line in grub help?
Comment 4 Diego 2011-03-19 07:10:09 UTC
(In reply to comment #3)
> Does booting with radeon.agpmode=-1 on the kernel command line in grub help?

It doesn't happen always, so I should live for some time with that option. I've lived for some time with "radeon.new_pll=0" to workaround the flickering and I've never had the crash anymore since then.
Flickering bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=677813

I'll try "radeon.agpmode=-1" and let you know ...
Comment 5 Alex Deucher 2011-03-19 10:49:39 UTC
radeon.new_pll=0 is not a valid parameter with either 2.6.37 or 2.6.38.  If you are setting that option, the drm is not loading and you are probably getting UMS with sw rendering.
Comment 6 Diego 2011-03-20 04:00:23 UTC
(In reply to comment #5)
> radeon.new_pll=0 is not a valid parameter with either 2.6.37 or 2.6.38.  If you
> are setting that option, the drm is not loading and you are probably getting
> UMS with sw rendering.

Exactly, radeon.new_pll=0 makes the system run with UMS and no 3D, so there's no flashing with UMS.

Turning to the specific problem, I've noticed some improvements using radeon.agpmode=-1:
- I've had several problems with KWin effects in KDE with elements of the panel disappearing and several strangenesses before specifying agpmode=-1, but now 3D seems to work perfectly;
- I've not experienced the crash anymore, but we're talking of only a couple of hours of usage 'till now;
- the flicker is still here.
Comment 7 Diego 2011-03-26 02:00:39 UTC
(In reply to comment #3)
> Does booting with radeon.agpmode=-1 on the kernel command line in grub help?

Confirmed: after a week of usage no problem so far. Just the flash keeps going, but that's a separate (DRM) issue, right?

So, I should put radeon.agpmode=-1 on grub,right?

Thanks for the help provided!
Comment 8 Alex Deucher 2011-03-26 09:31:48 UTC
(In reply to comment #7)
> (In reply to comment #3)
> > Does booting with radeon.agpmode=-1 on the kernel command line in grub help?
> 
> Confirmed: after a week of usage no problem so far. Just the flash keeps going,
> but that's a separate (DRM) issue, right?

Does the flash happen at regular intervals (like every 30 seconds or so)?  upowerd and one of the kde daemons poll the monitors at regular intervals to check if they are connected which can cause flickering.

> 
> So, I should put radeon.agpmode=-1 on grub,right?

Yes.  On the kernel command line in grub.
Comment 9 Diego 2011-03-26 12:56:57 UTC
(In reply to comment #8)
> Does the flash happen at regular intervals (like every 30 seconds or so)? 
> upowerd and one of the kde daemons poll the monitors at regular intervals to
> check if they are connected which can cause flickering.
> 

Yes, it more ore less quite regular... is there some test I could perform to see if it's upowerd / kded doing the polling? For instance: should it be present in kdm if it's what you're thinking of?
Comment 10 Alex Deucher 2011-03-27 12:52:17 UTC
Does the screen blink if you boot to runlevel 3 (or whatever the non-X runlevel is on your distro), i.e., boot to the kms console?  You can also try stopping upowerd or keventd (I think).
Comment 11 Diego 2011-03-31 12:24:07 UTC
(In reply to comment #10)
> Does the screen blink if you boot to runlevel 3 (or whatever the non-X runlevel
> is on your distro), i.e., boot to the kms console?  You can also try stopping
> upowerd or keventd (I think).

I confirm that the screen doesn't flicker in runlevel 3 (non-X).
Comment 12 Diego 2011-07-12 13:39:05 UTC
Screen flickering now happens almost only on KDE startup and not after, however I'll keep this report for the crash problem.

With "agpmode=-1" I experience no crash at all, but I should keep it even with kernel 2.6.39 because the crash still happens without the option.
Would it make sense to disable AGP mode by default for all the cards same as mine?
Comment 13 Michel Dänzer 2011-07-13 07:03:22 UTC
(In reply to comment #12)
> With "agpmode=-1" I experience no crash at all, but I should keep it even with
> kernel 2.6.39 because the crash still happens without the option.

How about agpmode=1 or 2?

> Would it make sense to disable AGP mode by default for all the cards same as
> mine?

I think it's worth considering disabling AGP by default for all cards with a PCIe GART (as opposed to the old PCI GART). It should be an overall win for stability, the main question is how it would impact performance on systems where AGP is stable.
Comment 14 Diego 2011-07-13 07:25:24 UTC
(In reply to comment #13)
> (In reply to comment #12)
> > With "agpmode=-1" I experience no crash at all, but I should keep it even with
> > kernel 2.6.39 because the crash still happens without the option.
> 
> How about agpmode=1 or 2?

I'll double check, but if I remeber correctly it was as bad as with no "agpmode" option.

> > Would it make sense to disable AGP mode by default for all the cards same as
> > mine?
> 
> I think it's worth considering disabling AGP by default for all cards with a
> PCIe GART (as opposed to the old PCI GART). It should be an overall win for
> stability, the main question is how it would impact performance on systems
> where AGP is stable.

If I'd have to choose between stability over performance for default settings I'd go for stability. Another option would be a blacklist for "bad" cards (as mine) or whitelist for "good" cards.
Moreover AGP cards are quite outdated, I woundn't expect people to use them for high performance applications with open driver.
Comment 15 Diego 2011-08-06 03:34:24 UTC
Wow, great news! I've tried again with the last Arch Linux updates and everything works fine!
I get no more problems without "agpmode=-1", and, as dmesg says, AGP is in 4x mode!

core/kernel26 2.6.39.3-1
extra/xorg-server 1.10.3-2
extra/xf86-video-ati 6.14.2-1
extra/mesa 7.11-1
extra/ati-dri 7.11-1

I'm closing this bug, as it's fixed for me.
Thanks for the great work, even if we don't know exactly we're the fix.
Comment 16 Diego 2011-08-06 03:35:25 UTC
Created attachment 49987 [details]
dmesg with AGP 4x working correctly


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