Bug 112255

Summary: Pageflip completion event has impossible msc related lockups
Product: xorg Reporter: Steve Wills <steve>
Component: Driver/AMDgpuAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED MOVED QA Contact: Xorg Project Team <xorg-team>
Severity: not set    
Priority: not set    
Version: unspecified   
Hardware: Other   
OS: FreeBSD   
Whiteboard:
i915 platform: i915 features:

Description Steve Wills 2019-11-12 17:14:48 UTC 
I've been seeing lockups with messages of this form:

(WW) AMDGPU(0): amdgpu_dri2_flip_event_handler: Pageflip completion event has impossible msc XXXXXXX < target_msc YYYYYYY

After commenting this line, it seems to have gone away:

https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu/blob/master/src/amdgpu_dri2.c#L494

That is, the messages are still logged, of course, but the lockups are gone because the client is no longer signaling failure to the client. I haven't seen any other adverse effects.

Should this be a warning only? One thing I noticed is the time is always 1 less than expected:

[ 20308.275] (WW) AMDGPU(0): amdgpu_dri2_flip_event_handler: Pageflip completion event has impossible msc 1868426 < target_msc 1868427
[716312.737] (WW) AMDGPU(0): amdgpu_dri2_flip_event_handler: Pageflip completion event has impossible msc 43628303 < target_msc 43628304
[752121.770] (WW) AMDGPU(0): amdgpu_dri2_flip_event_handler: Pageflip completion event has impossible msc 45776848 < target_msc 45776849
[833776.925] (WW) AMDGPU(0): amdgpu_dri2_flip_event_handler: Pageflip completion event has impossible msc 50676148 < target_msc 50676149

Perhaps there is an off by one error somewhere? Also I believe, but can't recall for sure sure, this problem only started once I enabled the TearFree option in the driver.
Comment 1 Martin Peres 2019-11-19 07:20:26 UTC 
-- GitLab Migration Automatic Message --

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