[PATCH 24/24] snd/hda: Protect concurrent display_power_status with a mutex

Chris Wilson chris at chris-wilson.co.uk
Mon Jan 14 08:52:01 UTC 2019


Just in case the audio linkage is swapped between components during the
runtime pm sequence, we need to protect the rpm tracking with a mutex.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Takashi Iwai <tiwai at suse.de>
Cc: Jani Nikula <jani.nikula at intel.com>
---
 include/sound/hdaudio.h    |  3 ++-
 sound/hda/hdac_component.c | 16 +++++++++++++---
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
index a438ec8e535b..497335b24e18 100644
--- a/include/sound/hdaudio.h
+++ b/include/sound/hdaudio.h
@@ -366,8 +366,9 @@ struct hdac_bus {
 
 	/* DRM component interface */
 	struct drm_audio_component *audio_component;
-	long display_power_status;
+	unsigned long display_power_status;
 	unsigned long display_power_active;
+	struct mutex display_power_lock;
 
 	/* parameters required for enhanced capabilities */
 	int num_streams;
diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c
index 2702548b788a..f40def1e2ca0 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->display_power_lock);
 	if (enable)
-		set_bit(idx, &bus->display_power_status);
+		__set_bit(idx, &bus->display_power_status);
 	else
-		clear_bit(idx, &bus->display_power_status);
+		__clear_bit(idx, &bus->display_power_status);
 
 	if (!acomp || !acomp->ops)
-		return;
+		goto unlock;
 
 	if (bus->display_power_status) {
 		if (!bus->display_power_active) {
@@ -98,6 +100,9 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
 			bus->display_power_active = 0;
 		}
 	}
+
+unlock:
+	mutex_unlock(&bus->display_power_lock);
 }
 EXPORT_SYMBOL_GPL(snd_hdac_display_power);
 
@@ -290,6 +295,9 @@ int snd_hdac_acomp_init(struct hdac_bus *bus,
 			     GFP_KERNEL);
 	if (!acomp)
 		return -ENOMEM;
+
+	mutex_init(&bus->display_power_lock);
+
 	acomp->audio_ops = aops;
 	bus->audio_component = acomp;
 	devres_add(dev, acomp);
@@ -336,6 +344,8 @@ int snd_hdac_acomp_exit(struct hdac_bus *bus)
 	bus->display_power_active = 0;
 	bus->display_power_status = 0;
 
+	mutex_destroy(&bus->display_power_lock);
+
 	component_master_del(dev, &hdac_component_master_ops);
 
 	bus->audio_component = NULL;
-- 
2.20.1



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