diff options
| author | Ben Skeggs <bskeggs@redhat.com> | 2017-05-11 17:13:29 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-25 14:30:10 +0200 |
| commit | 9d78e40f5f41ad1db1849f8d15acbda99d0871b4 (patch) | |
| tree | 690ab9a977e18441fb77969b1a9eb82e461387d1 /drivers/gpu/drm/nouveau | |
| parent | 5e07724c28f4e06fe42dd5b58bb6f9dd56510567 (diff) | |
drm/nouveau/tmr: avoid processing completed alarms when adding a new one
commit 330bdf62fe6a6c5b99a647f7bf7157107c9348b3 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu/drm/nouveau')
| -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 4e958db23ca0..74e40f1d8f52 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c @@ -80,12 +80,22 @@ 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 |