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| author |   Martin Peres <martin.peres@labri.fr> | 2014-03-14 00:26:52 +0100 |
|---|---|---|
| committer |   Ben Skeggs <bskeggs@redhat.com> | 2014-03-26 14:08:24 +1000 |
| commit | 61679fe153b2b9ea5b5e2ab93305419e85e99a9d (patch) | |
| tree | 4ee9e9b60320cc6f97c5b0dde16a30542d2f3111 /drivers/gpu/drm/nouveau/core/subdev | |
| parent | drm/nouveau: fix small thinko in vblank timestamping. (diff) | |
| download | linux-dev-61679fe153b2b9ea5b5e2ab93305419e85e99a9d.tar.xz linux-dev-61679fe153b2b9ea5b5e2ab93305419e85e99a9d.zip | |
drm/nouveau/pm/fan: drop the fan lock in fan_update() before rescheduling
This should fix a deadlock that has been reported to us where fan_update()
would hold the fan lock and try to grab the alarm_program_lock to reschedule
an update. On an other CPU, the alarm_program_lock would have been taken
before calling fan_update(), leading to a deadlock.
We should Cc: <stable@vger.kernel.org> # 3.9+
Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Tested-by: Timothée Ravier <tim@siosm.fr>
Tested-by: Boris Fersing (IRC nick fersingb, no public email address)
Signed-off-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/nouveau/core/subdev')
| -rw-r--r-- | drivers/gpu/drm/nouveau/core/subdev/therm/fan.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c b/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c index 95f6129eeede..29d4c417a5b3 100644 --- a/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c +++ b/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c @@ -54,8 +54,10 @@ nouveau_fan_update(struct nouveau_fan *fan, bool immediate, int target) /* check that we're not already at the target duty cycle */ duty = fan->get(therm); - if (duty == target) - goto done; + if (duty == target) { + spin_unlock_irqrestore(&fan->lock, flags); + return 0; + } /* smooth out the fanspeed increase/decrease */ if (!immediate && duty >= 0) { @@ -73,8 +75,15 @@ nouveau_fan_update(struct nouveau_fan *fan, bool immediate, int target) nv_debug(therm, "FAN update: %d\n", duty); ret = fan->set(therm, duty); - if (ret) - goto done; + if (ret) { + spin_unlock_irqrestore(&fan->lock, flags); + return ret; + } + + /* fan speed updated, drop the fan lock before grabbing the + * alarm-scheduling lock and risking a deadlock + */ + spin_unlock_irqrestore(&fan->lock, flags); /* schedule next fan update, if not at target speed already */ if (list_empty(&fan->alarm.head) && target != duty) { @@ -92,8 +101,6 @@ nouveau_fan_update(struct nouveau_fan *fan, bool immediate, int target) ptimer->alarm(ptimer, delay * 1000 * 1000, &fan->alarm); } -done: - spin_unlock_irqrestore(&fan->lock, flags); return ret; } |