Bug 46312 - [SNB] Linux LVDS Sequence Fail (likely edp panel sequencing fail)
Summary: [SNB] Linux LVDS Sequence Fail (likely edp panel sequencing fail)
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: unspecified
Hardware: Other Linux (All)
: medium normal
Assignee: Jesse Barnes
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-02-19 19:08 UTC by Yin Peng
Modified: 2017-07-24 23:02 UTC (History)
5 users (show)

See Also:
i915 platform:
i915 features:


Attachments
Linux LVDS Timing (1.30 MB, application/vnd.ms-excel)
2012-02-19 19:08 UTC, Yin Peng
no flags Details
edp power sequencing fix (1.10 KB, patch)
2012-04-16 15:49 UTC, Daniel Vetter
no flags Details | Splinter Review

Description Yin Peng 2012-02-19 19:08:35 UTC
Created attachment 57292 [details]
Linux LVDS Timing

We GFX card:  Intel 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)(8086:0116)

We environment:
kernel 3.0.7
xorg-x11-drv-intel-2.15.0
xorg-x11-server-1.10.0
libdrm-2.4.25

During entering the Linux OS, at a certain time, the signal of LVDS should be turned off first, then turn off LCD VDD.(Time interval should be 0-50ms)
But in testing we find the result is opposite. The signal of LVDS will be turned off after the LCD VDD. Time interval is 66ms. 
We don't if it's due to the graphic driver. 

There's a test result list in attachment.
Comment 1 Daniel Vetter 2012-02-20 05:11:45 UTC
This sounds like eDP power sequencing fun to me - I'm not aware of a VDD line on plain LVDS panels.
Comment 2 larry.su 2012-02-29 00:42:02 UTC
This is Larry from Sony. 
Currently we met this issue during test on our Linux project, test result with using driver "VESA" is pass, so it looks like this issue may caused by driver for Linux. anyone can support on this? thank you very much.
Comment 3 Daniel Vetter 2012-04-16 15:49:09 UTC
Created attachment 60102 [details] [review]
edp power sequencing fix

Can you please try this patch?
Comment 4 Jesse Barnes 2012-04-18 12:17:20 UTC
Larry or Peng, can you try Daniel's drm-intel-next-queued branch if his patch doesn't help?  The 3.0.7 kernel is really old, and lots of panel fixes have gone in since then.  Assuming a newer kernel works, you can bisect to the patch(es) that help and backport them to your environment.
Comment 5 Daniel Vetter 2012-05-22 12:06:06 UTC
Patch merged into drm-intel-fixes:

commit 600471fb43dad5962309bc41e5c59af249736664
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun May 20 17:14:50 2012 +0200

    drm/i915: enable vdd when switching off the eDP panel
Comment 6 Florian Mickler 2012-07-01 03:50:15 UTC
A patch referencing this bug report has been merged in Linux v3.5-rc1:

commit 6cb49835da0426f69a2931bc2a0a8156344b0e41
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun May 20 17:14:50 2012 +0200

    drm/i915: enable vdd when switching off the eDP panel
Comment 7 Florian Mickler 2012-08-20 21:57:03 UTC
A patch referencing a commit referencing this bug report has been merged in Linux v3.6-rc2:

commit 35a38556d900b9cb5dfa2529c93944b847f8a8a4
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Aug 12 22:17:14 2012 +0200

    drm/i915: reorder edp disabling to fix ivb MacBook Air


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