[alsa-devel] [PATCH v2 05/13] ALSA: hda: check stream decoupled register state

[Takashi Iwai]

On Wed, 07 Dec 2016 14:44:27 +0100,
jeeja.kp at intel.com wrote:
> 
> From: Jeeja KP <jeeja.kp at intel.com>
> 
> Check stream decoupled register value with requested value
> before decoupling/coupling the stream.
> 
> Signed-off-by: Jeeja KP <jeeja.kp at intel.com>
> ---
>  sound/hda/ext/hdac_ext_stream.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/sound/hda/ext/hdac_ext_stream.c b/sound/hda/ext/hdac_ext_stream.c
> index 3be051a..f35b006 100644
> --- a/sound/hda/ext/hdac_ext_stream.c
> +++ b/sound/hda/ext/hdac_ext_stream.c
> @@ -128,14 +128,17 @@ void snd_hdac_ext_stream_decouple(struct hdac_ext_bus *ebus,
>  {
>  	struct hdac_stream *hstream = &stream->hstream;
>  	struct hdac_bus *bus = &ebus->bus;
> +	u32 val;
> +	int mask = AZX_PPCTL_PROCEN(hstream->index);
>  
>  	spin_lock_irq(&bus->reg_lock);
> -	if (decouple)
> -		snd_hdac_updatel(bus->ppcap, AZX_REG_PP_PPCTL, 0,
> -				AZX_PPCTL_PROCEN(hstream->index));
> -	else
> -		snd_hdac_updatel(bus->ppcap, AZX_REG_PP_PPCTL,
> -					AZX_PPCTL_PROCEN(hstream->index), 0);
> +	val = ((readw(bus->ppcap + AZX_REG_PP_PPCTL) & mask) >> mask);

This looks wrong.
And you just need to know whether it's zero or not in below, so the
shift is anyway superfluous.


Takashi


> +	if (decouple && (val == 0))
> +		snd_hdac_updatel(bus->ppcap, AZX_REG_PP_PPCTL, mask, mask);
> +	else if (!decouple && (val > 0))
> +		snd_hdac_updatel(bus->ppcap, AZX_REG_PP_PPCTL, mask, 0);
> +
>  	stream->decoupled = decouple;
>  	spin_unlock_irq(&bus->reg_lock);
>  }
> -- 
> 2.5.0
>