Bug 26616 - [KMS] cannot find CRTC for LVDS; regression
Summary: [KMS] cannot find CRTC for LVDS; regression
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/Radeon (show other bugs)
Version: git
Hardware: x86 (IA32) Linux (All)
: medium major
Assignee: xf86-video-ati maintainers
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-02-17 12:31 UTC by Oldrich Jedlicka
Modified: 2010-02-21 15:09 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

Attachments
Output from `dmesg` (65.74 KB, text/plain)
2010-02-17 12:31 UTC, Oldrich Jedlicka 		no flags Details
Xorg.0.log (52.37 KB, text/plain)
2010-02-17 12:32 UTC, Oldrich Jedlicka 		no flags Details
fix shared ddc detection (1.56 KB, patch)
2010-02-18 23:16 UTC, Alex Deucher 		no flags Details | Splinter Review
dmesg (65.67 KB, text/plain)
2010-02-21 14:49 UTC, Oldrich Jedlicka 		no flags Details
Xorg.0.log (40.51 KB, text/plain)
2010-02-21 14:49 UTC, Oldrich Jedlicka 		no flags Details
View All

Description Oldrich Jedlicka 2010-02-17 12:31:47 UTC 
Created attachment 33367 [details]
Output from `dmesg`

There is currently a regression in drm-radeon-testing branch of GIT kernel source. The problem was originally fixed in bug #25150.

Symptoms:

LVDS shows only horizontal stripes during boot and changes color to white. Monitor connected to DVI-0 runs well, X.org starts and runs on DVI-0 only. Running

  xrandr --output LVDS --auto

shows "cannot find crtc for LVDS", but running 

  xrandr --output DVI-0 --off
  xrandr --output HDMI-0 --off
  xrandr --output LVDS --auto
  xrandr --output DVI-0 --auto

shows the screen correctly. I've bisected the drm-radeon-testing branch and the first problematic commit is bcc1c2a1d22974215e39dc87ce746ba9a39223e5 "drm/radeon/kms: add initial Evergreen support (Radeon HD 5xxx)".

dmesg and Xorg.log attached.
Comment 1 Oldrich Jedlicka 2010-02-17 12:32:47 UTC 
Created attachment 33368 [details]
Xorg.0.log
Comment 2 Oldrich Jedlicka 2010-02-17 12:34:52 UTC 
I have ATI Mobility Radeon HD 3470, I'm running xorg-server 1.7.5, libdrm git, xf86-video-ati git, mesa git, kernel branch radeon-drm-testing (as shown above).

The problem can be seen from the first moments of kernel switching to graphics during boot.
Comment 3 Alex Deucher 2010-02-18 23:16:58 UTC 
Created attachment 33410 [details] [review]
fix shared ddc detection

This should do the trick.
Comment 4 Oldrich Jedlicka 2010-02-21 14:48:02 UTC 
(In reply to comment #3)
> Created an attachment (id=33410) [details]
> fix shared ddc detection
> 
> This should do the trick.

Yes, that does the trick. Works for me. dmesg and Xorg.0.log attached.
Comment 5 Oldrich Jedlicka 2010-02-21 14:49:04 UTC 
Created attachment 33476 [details]
dmesg
Comment 6 Oldrich Jedlicka 2010-02-21 14:49:31 UTC 
Created attachment 33477 [details]
Xorg.0.log
Comment 7 Alex Deucher 2010-02-21 14:56:02 UTC 
Pushed upsteam.
Comment 8 Oldrich Jedlicka 2010-02-21 15:09:57 UTC 
And thanks for quick response (as usual) :-)

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