Bug 105201 - [SKL] LFP flickers continuously making it unusable
Summary: [SKL] LFP flickers continuously making it unusable
Status: CLOSED WORKSFORME
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: DRI git
Hardware: x86-64 (AMD64) All
: medium blocker
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-02-22 03:47 UTC by Shobhit Kumar
Modified: 2018-06-13 07:17 UTC (History)
3 users (show)

See Also:
i915 platform: SKL
i915 features: display/eDP


Attachments
Kernel Dmesg Logs for single display LFP boot. (110.49 KB, text/plain)
2018-02-22 03:47 UTC, Shobhit Kumar
no flags Details

Description Shobhit Kumar 2018-02-22 03:47:48 UTC
Created attachment 137520 [details]
Kernel Dmesg Logs for single display LFP boot.

The system configuration is as follows

Laptop - Hp pro-book 440 g3
SKU - SKL GT2
OS - Failed in same way for Elementary OS, Ubuntu 17.04
Native Resolution - 1366x768

System boots without flickers if we put nomodset, but not otherwise. Already tried almost latest drm-intel-next. Dmesg attached(for Ubuntu single display boot). Some experiments done which do not have any impact - disable rc6, FBC, DC states

Connecting an HDMI in dual display config, has HDMI working but thats on 10x7 config and not in its native 14x9. Local eDP still continues to flicker like crazy. Don't see any under run error logs.

Any patches to try just let me know and I can get the testing done. Right now short on time and resources to debug myself and any help/pointers will be very much appreciated. Thanks.
Comment 1 Shobhit Kumar 2018-02-24 15:12:07 UTC
Jani, can you help ?
Comment 2 Jani Nikula 2018-02-26 08:18:35 UTC
Hi Shobhit, to double check, you also see this problem with single display setup? i.e. this is not specific to dual display.

Please try a new kernel and/or i915.edp_vswing=1 or i915.edp_vswing=2 settings. Could be the DDI buffer translation settings, all I can think of now (since you already tried without fbc, psr, etc, and there are no underrun errors).
Comment 3 Shobhit Kumar 2018-02-26 12:09:59 UTC
Hi Jani,
Thanks for helping out on this. This problem happens in single display only. I just connected dual display for HDMI test and that worked but not at native resolution.

I will get your suggestions tested and update the results here.

Regards
Shobhit
Comment 4 Shobhit Kumar 2018-02-26 12:24:00 UTC
So the tests with edp_vswing=1 or 2 both failed with similar flickering. Got it tested on drm-intel-next of two weeks ago.

Do you think testing on latest will make a difference ?
Comment 5 Jani Nikula 2018-02-26 13:31:21 UTC
(In reply to Shobhit Kumar from comment #4)
> So the tests with edp_vswing=1 or 2 both failed with similar flickering. Got
> it tested on drm-intel-next of two weeks ago.
> 
> Do you think testing on latest will make a difference ?

I don't think so. But do try without the parameter on that same kernel.
Comment 6 Shobhit Kumar 2018-02-27 05:23:28 UTC
Without the parameters on same kernel anyways has the issue.
Comment 7 Jani Saarinen 2018-03-29 07:10:42 UTC
First of all. Sorry about spam.
This is mass update for our bugs. 

Sorry if you feel this annoying but with this trying to understand if bug still valid or not.
If bug investigation still in progress, please ignore this and I apologize!

If you think this is not anymore valid, please comment to the bug that can be closed.
If you haven't tested with our latest pre-upstream tree(drm-tip), can you do that also to see if issue is valid there still and if you cannot see issue there, please comment to the bug.
Comment 8 Jani Saarinen 2018-04-25 11:22:42 UTC
Closing, please re-open is issue still exists.
Comment 9 Shobhit Kumar 2018-06-13 07:17:54 UTC
(In reply to Jani Saarinen from comment #8)
> Closing, please re-open is issue still exists.

Okay, no issues. will test on latest drm-tip and if persists will open again


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