[PATCH 4.11 057/197] drm/nouveau/tmr: ack interrupt before processing alarms

[Greg Kroah-Hartman]

4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Skeggs <bskeggs@xxxxxxxxxx>

commit 3733bd8b407211739e72d051e5f30ad82a52c4bc upstream.

Fixes a race where we can miss an alarm that triggers while we're already
processing previous alarms.

Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c
@@ -76,8 +76,8 @@ nv04_timer_intr(struct nvkm_timer *tmr)
 	u32 stat = nvkm_rd32(device, NV04_PTIMER_INTR_0);
 
 	if (stat & 0x00000001) {
-		nvkm_timer_alarm_trigger(tmr);
 		nvkm_wr32(device, NV04_PTIMER_INTR_0, 0x00000001);
+		nvkm_timer_alarm_trigger(tmr);
 		stat &= ~0x00000001;
 	}