14139 – Output to external monitor is broken

Subject : [Bisected] Output to external monitor is broken (Re: Linux 2.6.31-rc9)
Submitter : "Carlos R. Mafra" <crmafra2@gmail.com>
Date : 2009年09月06日 14:22
References : http://marc.info/?l=linux-kernel&m=125224701520738&w=4
This entry is being used for tracking a regression from 2.6.30. Please don't
close it until the problem is fixed in the mainline.
Caused by:
commit f8aed700c6ec46ddade6570004ce25332283b306
Author: Ma Ling <ling.ma@intel.com>
Date: Mon Aug 24 13:50:24 2009 +0800
 drm/i915: Set crtc/clone mask in different output devices
 Signed-off-by: Ma Ling <ling.ma@intel.com>
 Reviewed-by : Jesse Barnes <jbarnes@virtuousgeek.org>
 Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
 Signed-off-by: Eric Anholt <eric@anholt.net>
First-Bad-Commit : f8aed700c6ec46ddade6570004ce25332283b306

Hi, Carlos
 Will you please add the boot option of "drm.debug=0x6" and attach the dmesg log on the working/failing kernel?
 Please boot the system with KMS disabled and attach the Xorg.0.log(It will be better if you can add the "modedebug" option in xorg.conf).
 Thanks.

Sorry that I give the incorrect boot option. It should be "drm.debug=0x07".
thanks.

Created attachment 23029 [details] 
dmesg from failing boot (with KMS and drm.debug=0x7)

Created attachment 23030 [details] 
dmesg from working 2.6.31-rc8-gX boot (with KMS and drm.debug=0x7)

Created attachment 23031 [details] 
Xorg.log without KMS, with ModeDebug

Could you attach dmesg of rc9 with drm.debug=15?
Are you sure f8aed700c6ec46ddade6570004ce25332283b306 is the final bisect result?
It looks can't be related...

(In reply to comment #6)
> Could you attach dmesg of rc9 with drm.debug=15?
Ok, it is on the way now.
 
> Are you sure f8aed700c6ec46ddade6570004ce25332283b306 is the final bisect
> result?
> It looks can't be related...
Yes, I am pretty sure. Bisection landed on the above commit and 
reverting it from 2.6.31-rc9 makes it work again. 
This is the bisect log, btw
git bisect start
# good: [adda766193ea1cf3137484a9521972d080d0b7af] Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
git bisect good adda766193ea1cf3137484a9521972d080d0b7af
# bad: [37d0892c5a94e208cf863e3b7bac014edee4346d] autofs4 - fix missed case when changing to use struct path
git bisect bad 37d0892c5a94e208cf863e3b7bac014edee4346d
# bad: [1a37f184fa7824982a5f434c06981ec46a66cef7] lmb: Also remove __init from lmb_end_of_RAM() declaration in lmb.h
git bisect bad 1a37f184fa7824982a5f434c06981ec46a66cef7
# bad: [f8aed700c6ec46ddade6570004ce25332283b306] drm/i915: Set crtc/clone mask in different output devices
git bisect bad f8aed700c6ec46ddade6570004ce25332283b306
# good: [bc5e5718acd7f7d000d913e619562767863610bf] drm/i915: Check if BIOS enabled dual-channel LVDS on 8xx, not only on 9xx
git bisect good bc5e5718acd7f7d000d913e619562767863610bf
# good: [27185ae1b795a4ba5e25b95fb5584e950545d774] drm/i915: Always use SDVO_B detect bit for SDVO output detection.
git bisect good 27185ae1b795a4ba5e25b95fb5584e950545d774

Created attachment 23037 [details] 
dmesg from failing 2.6.31-rc9 with drm.debug=15

I've just tested the patch proposed by Zhenyu Wang here
http://marc.info/?l=linux-kernel&m=125239311508274&w=2
and it fixed it!

Handled-By : Zhenyu Wang <zhenyuw@linux.intel.com>
Patch : http://patchwork.kernel.org/patch/46180/ 

Fixed by 7c8460db30dfd085ef3837c8fb02ecf2e718b983 in Linus' tree.