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

From: Greg Kroah-Hartman
Date: Tue May 23 2017 - 18:26:56 EST


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;
}