On Mon, 14 Jan 2019 18:37:53 +0100,
Chris Wilson wrote:
>
> 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.
It's not clear to me how does this happens.
Could you elaborate a bit more the scenario?
thanks,
Takashi
>
> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Takashi Iwai <tiwai@xxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> include/sound/hdaudio.h | 1 +
> sound/hda/hdac_component.c | 7 +++++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
> index 39761120ee76..497335b24e18 100644
> --- a/include/sound/hdaudio.h
> +++ b/include/sound/hdaudio.h
> @@ -368,6 +368,7 @@ struct hdac_bus {
> struct drm_audio_component *audio_component;
> 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..ea76c1de2927 100644
> --- a/sound/hda/hdac_component.c
> +++ b/sound/hda/hdac_component.c
> @@ -77,6 +77,7 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
> if (!acomp || !acomp->ops)
> return;
>
> + mutex_lock(&bus->display_power_lock);
> if (bus->display_power_status) {
> if (!bus->display_power_active) {
> unsigned long cookie = -1;
> @@ -98,6 +99,7 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
> bus->display_power_active = 0;
> }
> }
> + mutex_unlock(&bus->display_power_lock);
> }
> EXPORT_SYMBOL_GPL(snd_hdac_display_power);
>
> @@ -290,6 +292,9 @@ 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 +341,8 @@ 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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