drm-vblank: Always return true vblank count of scheduled vblank event.
drm-vblank: Always return true vblank count of scheduled vblank event.

This patch tries to make sure that the vbl.reply.sequence
vblank count for a queued or emitted vblank event always
corresponds to the true vblank count of queueing/emission, so
the ddx can rely on the returned target_msc for consistency
checks and implementation of swap_intervals in glXSwapBuffers().

Without this there is a small race-condition between the
userspace ddx queueing a vblank event and the vblank
counter incrementing before the event gets queued in
the kernel.

Signed-off-by: Mario Kleiner <72d071d150c24522961f76cddfa9e5d9130c5153@tuebingen.mpg.de>
Acked-by: Jesse Barnes <bc7add126c2dbb8382bf1c28ac262b9363a32706@virtuousgeek.org>
Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas