redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

drm/radeon: Make classic pageflip completion path less racy.

Browse source 
Need to protect mmio flip programming by event lock as well.

Need to also first enable pflip irq, then mmio program,
otherwise a flip completion may get unnoticed in the vblank
of actual completion if the flip is programmed, but
radeon_flip_work_func gets preempted immediately after
mmio programming and before vblank. In that case the
vblank irq handler wouldn't run radeon_crtc_handle_vblank()
with the completion check routine, miss the completed flip,
and only notice one vblank after actual completion, causing
a false/delayed report of flip completion.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Mario Kleiner 2014-07-17 02:24:45 +02:00 committed by Alex Deucher
parent 826484977c
commit 5f87e090a7
1 changed files with 3 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/gpu/drm/radeon/radeon_display.c
View file

@ -407,15 +407,15 @@ static void radeon_flip_work_func(struct work_struct *__work)
radeon_fence_unref(&work->fence);
}
/* do the flip (mmio) */
radeon_page_flip(rdev, radeon_crtc->crtc_id, work->base);
/* We borrow the event spin lock for protecting flip_status */
spin_lock_irqsave(&crtc->dev->event_lock, flags);
/* set the proper interrupt */
radeon_irq_kms_pflip_irq_get(rdev, radeon_crtc->crtc_id);
/* do the flip (mmio) */
radeon_page_flip(rdev, radeon_crtc->crtc_id, work->base);
radeon_crtc->flip_status = RADEON_FLIP_SUBMITTED;
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
up_read(&rdev->exclusive_lock);