From: Keith Packard <keithp@keithp.com>
Date: Thu, 7 Nov 2013 22:17:12 +0000 (-0800)
Subject: present: Round fake MSC computations intead of truncating
X-Git-Tag: xorg-server-1.14.99.903~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4f3c37a1f17ffcfbbff71d217e1caad3d0148c90;p=platform%2Fupstream%2Fxorg-server.git

present: Round fake MSC computations intead of truncating

If the timer fired too early, we'd sometimes mis-compute the MSC for
fake vblanks. Rounding the computation to the nearest MSC fixes this nicely.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
---

diff --git a/present/present_fake.c b/present/present_fake.c
index a677592..e550e98 100644
--- a/present/present_fake.c
+++ b/present/present_fake.c
@@ -42,7 +42,7 @@ present_fake_get_ust_msc(ScreenPtr screen, uint64_t *ust, uint64_t *msc)
     present_screen_priv_ptr screen_priv = present_screen_priv(screen);
 
     *ust = GetTimeInMicros();
-    *msc = *ust / screen_priv->fake_interval;
+    *msc = (*ust + screen_priv->fake_interval / 2) / screen_priv->fake_interval;
     return Success;
 }