Bug 56401 - [IVB eDP stable-regression] laptop screen does not come up until a suspend/resume cycle happens.
Summary: [IVB eDP stable-regression] laptop screen does not come up until a suspend/re...
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: x86-64 (AMD64) Linux (All)
: high normal
Assignee: Daniel Vetter
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-10-25 16:24 UTC by roberth
Modified: 2017-07-24 22:59 UTC (History)
5 users (show)

See Also:
i915 platform:
i915 features:

Attachments
dmesg after reproducing it with drm.debug=0xe (104.92 KB, text/plain)
2012-10-25 16:24 UTC, roberth 		no flags Details
intel_reg_dumper output (working) (11.58 KB, text/plain)
2012-10-25 16:24 UTC, roberth 		no flags Details
intel_reg_dumper output (failing) (11.58 KB, text/plain)
2012-10-25 16:25 UTC, roberth 		no flags Details
3.6.3 dmesg (108.57 KB, text/plain)
2012-10-25 19:24 UTC, roberth 		no flags Details
edid (128 bytes, application/octet-stream)
2012-11-09 15:19 UTC, roberth 		no flags Details
View All

Description roberth 2012-10-25 16:24:06 UTC 
Created attachment 69076 [details]
dmesg after reproducing it with drm.debug=0xe

This commit causes a lenovo v490u to have a black screen after booting

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=4344b813f105a19f793f1fd93ad775b784648b95 

It's working properly in 3.7, but 3.6 is broken without reverting that, and that commit was backported to the stable kernels which are now broken also. Suspending/resuming the machine after booting brings the display back up.

(working with revert)
[   12.179335] [drm:intel_choose_pipe_bpp_dither], clamping display bpc (was -1) to eDP (6)
[   12.179337] [drm:intel_choose_pipe_bpp_dither], setting pipe bpc to 8 (max display bpc 6)

(failing)
[   14.264823] [drm:intel_choose_pipe_bpp_dither], setting pipe bpc to 8 (max display bpc 8)
Comment 1 roberth 2012-10-25 16:24:52 UTC 
Created attachment 69077 [details]
intel_reg_dumper output (working)
Comment 2 roberth 2012-10-25 16:25:16 UTC 
Created attachment 69078 [details]
intel_reg_dumper output (failing)
Comment 3 Daniel Vetter 2012-10-25 18:52:31 UTC 
Please double-check whether your 3.6 tree contains:

commit 0c96c65b48fba3ffe9822a554cbc0cd610765cd5
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Sep 26 18:43:10 2012 +0300

    drm/i915: use adjusted_mode instead of mode for checking the 6bpc force flag

This should fix fallout from the cited commit.
Comment 4 roberth 2012-10-25 19:24:19 UTC 
No luck unfortunately, tried 3.2.32 and 3.6.3 that both contain that commit and they have the same problem.
Comment 5 roberth 2012-10-25 19:24:49 UTC 
Created attachment 69090 [details]
3.6.3 dmesg
Comment 6 Jani Nikula 2012-11-07 11:20:13 UTC 
Related to https://bugzilla.kernel.org/show_bug.cgi?id=47641

Robert, please add the hex dump of your EDID from /sys/class/drm/*/edid, where * is your display.
Comment 7 roberth 2012-11-09 15:19:20 UTC 
Created attachment 69821 [details]
edid

00ffffffffffff000dae771400000000
02160103801f11780a2b359757548f29
23505400000001010101010101010101
010101010101da1d56e250002030442d
470035ae10000018e01856e250002030
442d470035ae10000018000000fe0043
4d4e0a202020202020202020000000fe
004e3134304247452d4c41320a200051
Comment 8 roberth 2012-11-11 15:56:01 UTC 
Another eDP machine (dell e6510) broken by this commit on 

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1077064
Comment 9 Daniel Vetter 2012-11-13 12:15:59 UTC 
Revert merged to -fixes:

commit 2f4f649a69a9eb51f6e98130e19dd90a260a4145
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Mon Nov 12 14:33:44 2012 +0200

    drm/i915: do not ignore eDP bpc settings from vbt

Please yell if this is still an issue for you.

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