swap_target is an out-parameter that needs to be set to the value that
SBC will take on after this SwapBuffers request completes.
However, it was also being used as a temporary variable to hold the MSC
at which the SwapBuffers request got scheduled to occur. This confusion
makes it harder to reason about whether swap_target is being set
correctly for its out-parameter usage. (Hint: It isn't.)
For the latter use, it makes more sense to use the existing target_msc
variable, which already has the right value unless target_msc, divisor,
and remainder are all 0, in which case we can set it using swap_interval
as usual.
Signed-off-by: Jamey Sharp <ja...@minilop.net>
Signed-off-by: Theo Hill <theo0...@gmail.com>
---
hw/xfree86/dri2/dri2.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
index 729a323..962f40c 100644
--- a/hw/xfree86/dri2/dri2.c
+++ b/hw/xfree86/dri2/dri2.c
@@ -1149,17 +1149,13 @@ DRI2SwapBuffers(ClientPtr client, DrawablePtr pDraw,
CARD64 target_msc,
* we have to account for the current swap count, interval, and the
* number of pending swaps.
*/
- *swap_target = pPriv->last_swap_target + pPriv->swap_interval;
+ target_msc = pPriv->last_swap_target + pPriv->swap_interval;
}
- else {
- /* glXSwapBuffersMscOML could have a 0 target_msc, honor it */
- *swap_target = target_msc;
- }
pPriv->swapsPending++;
ret = (*ds->ScheduleSwap) (client, pDraw, pDestBuffer, pSrcBuffer,
- swap_target, divisor, remainder, func, data);
+ &target_msc, divisor, remainder, func, data);
if (!ret) {
pPriv->swapsPending--; /* didn't schedule */
xf86DrvMsg(pScreen->myNum, X_ERROR,
@@ -1167,7 +1163,7 @@ DRI2SwapBuffers(ClientPtr client, DrawablePtr pDraw,
CARD64 target_msc,
return BadDrawable;
}
- pPriv->last_swap_target = *swap_target;
+ pPriv->last_swap_target = target_msc;
/* According to spec, return expected swapbuffers count SBC after this swap
* will complete.
--
1.8.5.3
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