[PATCH 2/2] present: Fix use of vsynced pageflips and honor PresentOptionAsync. (v4)

[Mario Kleiner]

Pageflips for Pixmap presents were not synchronized to vblank on
drivers with support for PresentCapabilityAsync, due to some
missing init for vblank->sync_flips. The PresentOptionAsync
flag was completely ignored for pageflipped presents.

Vsynced flips only worked by accident on the intel-ddx, as that
driver doesn't have PresentCapabilityAsync support.

On nouveau-ddx, which supports PresentCapabilityAsync, this
always caused non-vsynced pageflips with pretty ugly tearing.

This patch fixes the problem, as tested on top of XOrg 1.16.2
on nouveau and intel.

v4: Add additional PresentCapabilityAsync caps check, as
suggested by Eric Anholt.

Please also apply to XOrg 1.17 and XOrg 1.16.2 stable.

Applying on top of XOrg 1.16.2 requires cherry-picking
commit 2051514652481a83bd7cf22e57cb0fcd40333f33
which trivially fixes lack of support for protocol option
PresentOptionCopy - get two bug fixes for the price of one!

Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
Reviewed-by: Eric Anholt <eric at anholt.net>
---
 present/present.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/present/present.c b/present/present.c
index e5d3fd5..e27fe30 100644
--- a/present/present.c
+++ b/present/present.c
@@ -834,10 +834,13 @@ present_pixmap(WindowPtr window,
     vblank->notifies = notifies;
     vblank->num_notifies = num_notifies;
 
-    if (!screen_priv->info || !(screen_priv->info->capabilities & PresentCapabilityAsync))
+    if (!(options & PresentOptionAsync))
         vblank->sync_flip = TRUE;
 
     if (!(options & PresentOptionCopy) &&
+        !((options & PresentOptionAsync) &&
+          (!screen_priv->info ||
+           !(screen_priv->info->capabilities & PresentCapabilityAsync))) &&
         pixmap != NULL &&
         present_check_flip (target_crtc, window, pixmap, vblank->sync_flip, valid, x_off, y_off))
     {
-- 
2.1.0