[alsa-devel] [PATCH v5 03/12] ALSA: control: Add init callback for kcontrol

[Takashi Iwai]

At Sat, 6 Sep 2014 15:21:24 +0100,
Mark Brown wrote:
> 
> On Tue, Sep 02, 2014 at 06:05:58PM +0530, Subhransu S. Prusty wrote:
> > Some controls need to initialize stuffs like pvt data, so they need a
> > callback if the control creation is successful.
> 
> Adding Takashi - this is ALSA core code so he needs to review it.

This would bloat effectively the data size of all sound drivers, so I
can't ack it without more proper reasoning.  That is, please convince
me why this change must be taken for the cost of size bloat of all
sound drivers.  Can't you do it in the caller side of snd_ctl_add()
like many other drivers already do?


thanks,

Takashi

> > Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty at intel.com>
> > Signed-off-by: Vinod Koul <vinod.koul at intel.com>
> > ---
> >  include/sound/control.h | 3 +++
> >  sound/core/control.c    | 7 +++++++
> >  2 files changed, 10 insertions(+)
> > 
> > diff --git a/include/sound/control.h b/include/sound/control.h
> > index 0426139..1389f69 100644
> > --- a/include/sound/control.h
> > +++ b/include/sound/control.h
> > @@ -30,6 +30,7 @@ struct snd_kcontrol;
> >  typedef int (snd_kcontrol_info_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo);
> >  typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
> >  typedef int (snd_kcontrol_put_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
> > +typedef int (snd_kcontrol_init_t) (struct snd_kcontrol * kcontrol);
> >  typedef int (snd_kcontrol_tlv_rw_t)(struct snd_kcontrol *kcontrol,
> >  				    int op_flag, /* SNDRV_CTL_TLV_OP_XXX */
> >  				    unsigned int size,
> > @@ -52,6 +53,7 @@ struct snd_kcontrol_new {
> >  	snd_kcontrol_info_t *info;
> >  	snd_kcontrol_get_t *get;
> >  	snd_kcontrol_put_t *put;
> > +	snd_kcontrol_init_t *init;
> >  	union {
> >  		snd_kcontrol_tlv_rw_t *c;
> >  		const unsigned int *p;
> > @@ -71,6 +73,7 @@ struct snd_kcontrol {
> >  	snd_kcontrol_info_t *info;
> >  	snd_kcontrol_get_t *get;
> >  	snd_kcontrol_put_t *put;
> > +	snd_kcontrol_init_t *init;
> >  	union {
> >  		snd_kcontrol_tlv_rw_t *c;
> >  		const unsigned int *p;
> > diff --git a/sound/core/control.c b/sound/core/control.c
> > index b961134..9d30663 100644
> > --- a/sound/core/control.c
> > +++ b/sound/core/control.c
> > @@ -256,6 +256,7 @@ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
> >  	kctl.info = ncontrol->info;
> >  	kctl.get = ncontrol->get;
> >  	kctl.put = ncontrol->put;
> > +	kctl.init = ncontrol->init;
> >  	kctl.tlv.p = ncontrol->tlv.p;
> >  	kctl.private_value = ncontrol->private_value;
> >  	kctl.private_data = private_data;
> > @@ -362,6 +363,12 @@ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
> >  		err = -ENOMEM;
> >  		goto error;
> >  	}
> > +	if (kcontrol->init) {
> > +		err = kcontrol->init(kcontrol);
> > +		if (err < 0)
> > +			goto error;
> > +	}
> > +
> >  	list_add_tail(&kcontrol->list, &card->controls);
> >  	card->controls_count += kcontrol->count;
> >  	kcontrol->id.numid = card->last_numid + 1;
> > -- 
> > 1.9.0
> > 
> > 
> [2 Digital signature <application/pgp-signature (7bit)>]
>