diff options
| author | Ben Skeggs <bskeggs@redhat.com> | 2017-05-11 17:13:29 +1000 |
|---|---|---|
| committer | Ben Skeggs <bskeggs@redhat.com> | 2017-05-12 08:32:58 +1000 |
| commit | 330bdf62fe6a6c5b99a647f7bf7157107c9348b3 (patch) | |
| tree | 1fe7a3da274d6a66fd77d4326704b9232fa3a07c | |
| parent | 9fc64667ee48c9a25e7dca1a6bcb6906fec5bcc5 (diff) | |
| download | linux-330bdf62fe6a6c5b99a647f7bf7157107c9348b3.tar.gz | |
drm/nouveau/tmr: avoid processing completed alarms when adding a new one
The idea here was to avoid having to "manually" program the HW if there's a new earliest alarm. This was lazy and bad, as it leads to loads of fun races between inter-related callers (ie. therm). Turns out, it's not so difficult after all. Go figure ;) Signed-off-by: Ben Skeggs <bskeggs@redhat.com> Cc: stable@vger.kernel.org
| -rw-r--r-- | drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c index d898787d514c..f2a86eae0a0d 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c @@ -86,12 +86,22 @@ nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm) if (list->timestamp > alarm->timestamp) break; } + list_add_tail(&alarm->head, &list->head); + + /* Update HW if this is now the earliest alarm. */ + list = list_first_entry(&tmr->alarms, typeof(*list), head); + if (list == alarm) { + tmr->func->alarm_init(tmr, alarm->timestamp); + /* This shouldn't happen if callers aren't stupid. + * + * Worst case scenario is that it'll take roughly + * 4 seconds for the next alarm to trigger. + */ + WARN_ON(alarm->timestamp <= nvkm_timer_read(tmr)); + } } spin_unlock_irqrestore(&tmr->lock, flags); - - /* process pending alarms */ - nvkm_timer_alarm_trigger(tmr); } void |