From b00d435ddf2e9817e33bfd5f7e9b905442dc23c7 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Mon, 8 Mar 2010 12:41:25 -0800 Subject: [PATCH] DRI2: handle swapsPending better Avoid a potential swapsPending underflow by incrementing it before ScheduleSwap, which may complete it immediately. And be sure to decrement it again in case the schedule failed. Reported-by: Mario Kleiner Reviewed-by: Mario Kleiner Signed-off-by: Jesse Barnes --- hw/xfree86/dri2/dri2.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c index 3fc7f4ee29..8a671226fd 100644 --- a/hw/xfree86/dri2/dri2.c +++ b/hw/xfree86/dri2/dri2.c @@ -654,15 +654,16 @@ DRI2SwapBuffers(ClientPtr client, DrawablePtr pDraw, CARD64 target_msc, *swap_target = target_msc; } + pPriv->swapsPending++; ret = (*ds->ScheduleSwap)(client, pDraw, pDestBuffer, pSrcBuffer, swap_target, divisor, remainder, func, data); if (!ret) { + pPriv->swapsPending--; /* didn't schedule */ xf86DrvMsg(pScreen->myNum, X_ERROR, "[DRI2] %s: driver failed to schedule swap\n", __func__); return BadDrawable; } - pPriv->swapsPending++; pPriv->last_swap_target = *swap_target; /* According to spec, return expected swapbuffers count SBC after this swap