xf86-video-modesetting: Fix ms_queue_vblank(flags = MS_QUEUE_RELATIVE)

Change 677c32bc refactored all usages of drmWaitVBlank() into a helper function,
ms_queue_vblank().

ms_queue_vblank() takes in an MS_QUEUE_RELATIVE flag to indicate that the
sequence number is relative rather than absolute, but still treats the actual
sequence number as absolute, passing it through ms_crtc_msc_to_kernel_msc()
unconditionally before calling drmWaitVBlank().

ms_crtc_msc_to_kernel_msc() works by subtracting a vblank offset from the
provided sequence number, which only makes sense for absolute sequence numbers.
In the case of PRIME Sync, drmmode_SharedPixmapPrsentOnVBlank() passes in 1,
which results in a large negative vblank offset. After subtracting, we're left
with a relative sequence number of 100,000+, i.e. wait for 100,000+ vblanks...

In the relative case we want to pass in the sequence number unmodified. Simply
add a check to do this.

Signed-off-by: Alex Goins <agoins@nvidia.com>
Reviewed-by: Keith Packard <keithp@keithp.com>

0 files changed, 0 insertions, 0 deletions