[PATCH] drm/vc4: Make pageflip completion handling more robust.

[Eric Anholt]

Mario Kleiner <mario.kleiner.de at gmail.com> writes:

> Protect both the setup of the pageflip event and the
> latching of the new requested displaylist head pointer
> by the event lock, so we can't get into a situation
> where vc4_atomic_flush latches the new display list via
> HVS_WRITE, then immediately gets preempted before queueing
> the pageflip event, then the page-flip completes in hw and
> the vc4_crtc_handle_page_flip() runs and no-ops due to
> lack of a pending pageflip event, then vc4_atomic_flush
> continues and only then queues the pageflip event - after
> the page flip handling already no-oped. This would cause
> flip completion handling only at the next vblank - one
> frame too late.

This patch is:

Reviewed-by: Eric Anholt <eric at anholt.net>

I'll try to get a pull request sent out for this shortly.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20160602/75c8b8e7/attachment.sig>