ddx/ati: Fix reporting of pageflip completion events on multi-head.

When a drawable is page-flipped on multiple crtc's (fullscreen
drawable on mirror-mode or multi-head x-screen), only one pageflip
event is finally delivered, after the last participating crtc signals
flip completion, this to avoid visual corruption.

Old code returned vblank count and timestamps of flip completion
of this last crtc, instead of the values of the "master crtc", the
one that was used for initially scheduling/triggering the pagflip
via vblank events. (master = radeon_dri2_drawable_crtc(drawable))

This patch makes sure that the pageflip completion values of the
"master" crtc are returned, otherwise client applications will
get confused by the random (msc, ust) values returned by whichever
crtc was the last to complete its flip. Without this, the returned
values change randomly and jump forward and backward in time and
count.

The patch also implements a consistency check on returned vblank
count values of pageflip completion. Impossible values are detected,
a x-warning is logged and returned (msc,ust) values are marked invalid,
so clients could perform error handling. Such a warning would indicate
bugs in the pageflip completion routine of future kms drivers or the
ddx to aid driver debugging.

Signed-off-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>

0 files changed, 0 insertions, 0 deletions