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| author | Takashi Iwai <tiwai@suse.de> | 2019-04-10 12:49:55 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2019-04-10 15:23:36 +0200 |
| commit | d7a181da2dfa3190487c446042ba01e07d851c74 (patch) | |
| tree | c2c281018d0a0dd56e792e0fca49af8313d5a30b /sound | |
| parent | cae30527901d9590db0e12ace994c1d58bea87fd (diff) | |
| download | lwn-d7a181da2dfa3190487c446042ba01e07d851c74.tar.gz lwn-d7a181da2dfa3190487c446042ba01e07d851c74.zip | |
ALSA: hda: Fix racy display power access
snd_hdac_display_power() doesn't handle the concurrent calls carefully
enough, and it may lead to the doubly get_power or put_power calls,
when a runtime PM and an async work get called in racy way.
This patch addresses it by reusing the bus->lock mutex that has been
used for protecting the link state change in ext bus code, so that it
can protect against racy display state changes. The initialization of
bus->lock was moved from snd_hdac_ext_bus_init() to
snd_hdac_bus_init() as well accordingly.
Testcase: igt/i915_pm_rpm/module-reload #glk-dsi
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/hda/ext/hdac_ext_bus.c | 1 | ||||
| -rw-r--r-- | sound/hda/hdac_bus.c | 1 | ||||
| -rw-r--r-- | sound/hda/hdac_component.c | 6 |
3 files changed, 6 insertions, 2 deletions
diff --git a/sound/hda/ext/hdac_ext_bus.c b/sound/hda/ext/hdac_ext_bus.c index 9c37d9af3023..ec7715c6b0c0 100644 --- a/sound/hda/ext/hdac_ext_bus.c +++ b/sound/hda/ext/hdac_ext_bus.c @@ -107,7 +107,6 @@ int snd_hdac_ext_bus_init(struct hdac_bus *bus, struct device *dev, INIT_LIST_HEAD(&bus->hlink_list); bus->idx = idx++; - mutex_init(&bus->lock); bus->cmd_dma_state = true; return 0; diff --git a/sound/hda/hdac_bus.c b/sound/hda/hdac_bus.c index 012305177f68..ad8eee08013f 100644 --- a/sound/hda/hdac_bus.c +++ b/sound/hda/hdac_bus.c @@ -38,6 +38,7 @@ int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev, INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events); spin_lock_init(&bus->reg_lock); mutex_init(&bus->cmd_mutex); + mutex_init(&bus->lock); bus->irq = -1; return 0; } diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c index a6d37b9d6413..6b5caee61c6e 100644 --- a/sound/hda/hdac_component.c +++ b/sound/hda/hdac_component.c @@ -69,13 +69,15 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable) dev_dbg(bus->dev, "display power %s\n", enable ? "enable" : "disable"); + + mutex_lock(&bus->lock); if (enable) set_bit(idx, &bus->display_power_status); else clear_bit(idx, &bus->display_power_status); if (!acomp || !acomp->ops) - return; + goto unlock; if (bus->display_power_status) { if (!bus->display_power_active) { @@ -92,6 +94,8 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable) bus->display_power_active = false; } } + unlock: + mutex_unlock(&bus->lock); } EXPORT_SYMBOL_GPL(snd_hdac_display_power); |