[alsa-devel] [PATCH v2 2/2] ALSA: compress: Pass id string to snd_compress_new

[Takashi Iwai]

On Wed, 25 Nov 2015 12:07:01 +0100,
Richard Fitzgerald wrote:
> 
> On Wed, 2015-11-25 at 11:49 +0100, Takashi Iwai wrote:
> > On Wed, 25 Nov 2015 11:46:16 +0100,
> > Richard Fitzgerald wrote:
> > > 
> > > Make snd_compress_new take an id string (like snd_pcm_new).
> > > This string can be included in the procfs info.
> > > 
> > > This patch also updates soc_new_compress() to create an ID
> > > based on the stream and dai name, as done for PCM streams.
> > > 
> > > Signed-off-by: Richard Fitzgerald <rf at opensource.wolfsonmicro.com>
> > > ---
> > >  include/sound/compress_driver.h | 2 +-
> > >  sound/core/compress_offload.c   | 6 +++++-
> > >  sound/soc/soc-compress.c        | 8 +++++++-
> > >  3 files changed, 13 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
> > > index 85c4237..c0abcdc 100644
> > > --- a/include/sound/compress_driver.h
> > > +++ b/include/sound/compress_driver.h
> > > @@ -163,7 +163,7 @@ struct snd_compr {
> > >  int snd_compress_register(struct snd_compr *device);
> > >  int snd_compress_deregister(struct snd_compr *device);
> > >  int snd_compress_new(struct snd_card *card, int device,
> > > -			int type, struct snd_compr *compr);
> > > +			int type, const char *id, struct snd_compr *compr);
> > >  
> > >  /* dsp driver callback apis
> > >   * For playback: driver should call snd_compress_fragment_elapsed() to let the
> > > diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> > > index 282b69a..326ea0e 100644
> > > --- a/sound/core/compress_offload.c
> > > +++ b/sound/core/compress_offload.c
> > > @@ -976,7 +976,7 @@ static int snd_compress_dev_free(struct snd_device *device)
> > >   * @compr: compress device pointer
> > >   */
> > >  int snd_compress_new(struct snd_card *card, int device,
> > > -			int dirn, struct snd_compr *compr)
> > > +			int dirn, const char *id, struct snd_compr *compr)
> > >  {
> > >  	static struct snd_device_ops ops = {
> > >  		.dev_free = snd_compress_dev_free,
> > > @@ -989,6 +989,10 @@ int snd_compress_new(struct snd_card *card, int device,
> > >  	compr->device = device;
> > >  	compr->direction = dirn;
> > >  
> > > +	if (IS_ENABLED(CONFIG_SND_VERBOSE_PROCFS))
> > 
> > This should be #if.  Otherwise the compile would fail (as already
> > kbuild bot spotted).
> > 
> > 
> > Takashi
> > 
> 
> Builds ok for me, this will become if(false) if it's not enabled so the
> compiler will strip it out

It will be dropped, but the code is still parsed by the compiler, thus
it shall fail.  It's the difference from the preprocessor and the
normal if block.

> - some maintainers prefer that to #if and I'm
> used to being told to use this style instead of #if, so who knows what
> today's coding style is :) The build bot failure was for a different
> reason.

Depends.  For a case like this, where the access itself becoming
invalid, we must not make the code path parsed.  Instead, it has to be
disabled by preprocessor.

OTOH, having a disabled if block often helps to avoid the compile
warnings for unused variables or functions.  So it's case-by-case.


Takashi

> 
> Anyway, I can change to #if if you prefer that.
> 
> > > +		if (id)
> > > +			strlcpy(compr->id, id, sizeof(compr->id));
> > > +
> > >  	snd_device_initialize(&compr->dev, card);
> > >  	dev_set_name(&compr->dev, "comprC%iD%i", card->number, device);
> > >  
> > > diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
> > > index 12a9820..fffbe6f 100644
> > > --- a/sound/soc/soc-compress.c
> > > +++ b/sound/soc/soc-compress.c
> > > @@ -689,7 +689,13 @@ int snd_soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num)
> > >  		compr->ops->copy = soc_compr_copy;
> > >  
> > >  	mutex_init(&compr->lock);
> > > -	ret = snd_compress_new(rtd->card->snd_card, num, direction, compr);
> > > +
> > > +	snprintf(new_name, sizeof(new_name), "%s %s-%d",
> > > +		 rtd->dai_link->stream_name,
> > > +		 rtd->codec_dai->name, num);
> > > +
> > > +	ret = snd_compress_new(rtd->card->snd_card, num, direction,
> > > +				new_name, compr);
> > >  	if (ret < 0) {
> > >  		pr_err("compress asoc: can't create compress for codec %s\n",
> > >  			codec->component.name);
> > > -- 
> > > 1.9.1
> > > 
> > > 
> 
>