[alsa-devel] [PATCH v8 2/7] ALSA: Jack: refactoring snd_kctl_jack_new to support embedded kctl

[Jie, Yang]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Wednesday, April 22, 2015 8:58 PM
> To: Jie, Yang
> Cc: broonie at kernel.org; alsa-devel at alsa-project.org; Girdwood, Liam R;
> tanu.kaskinen at linux.intel.com
> Subject: Re: [PATCH v8 2/7] ALSA: Jack: refactoring snd_kctl_jack_new to
> support embedded kctl
> 
> At Wed, 22 Apr 2015 12:40:43 +0000,
> Jie, Yang wrote:
> >
> > > -----Original Message-----
> > > From: Takashi Iwai [mailto:tiwai at suse.de]
> > > Sent: Wednesday, April 22, 2015 7:33 PM
> > > To: Jie, Yang
> > > Cc: broonie at kernel.org; alsa-devel at alsa-project.org; Girdwood, Liam
> > > R; tanu.kaskinen at linux.intel.com
> > > Subject: Re: [PATCH v8 2/7] ALSA: Jack: refactoring
> > > snd_kctl_jack_new to support embedded kctl
> > >
> > > At Wed, 22 Apr 2015 14:03:48 +0800,
> > > Jie Yang wrote:
> > > >
> > > > Move available index get part into snd_kctl_jack_new(), also add
> > > > kctl name regenerating func to remove redundant " Jack" which is
> > > > passed in wrongly in some cases.
> > >
> > > The subject doesn't match with this description well.
> >
> > How about changing them as below:
> >
> > ALSA: Jack: handle jack embedded kcontrol creating within ctljack
> >
> > In ctljack.c, add function get_available_index() to allocate index for
> > new kcontrol, and jack_kctl_name_gen() to remove redundant " Jack"
> > which is passed in wrongly in some cases.
> >
> > >
> > >
> > > > Signed-off-by: Jie Yang <yang.jie at intel.com>
> > > > ---
> > > >  include/sound/control.h  |  2 +-
> > > >  sound/core/ctljack.c     | 39
> +++++++++++++++++++++++++++++++++++-
> > > ---
> > > >  sound/core/jack.c        |  2 +-
> > > >  sound/pci/hda/hda_jack.c |  2 +-
> > > >  4 files changed, 38 insertions(+), 7 deletions(-)
> > > >
> > > > diff --git a/include/sound/control.h b/include/sound/control.h
> > > > index
> > > > 75f3054..58751a0 100644
> > > > --- a/include/sound/control.h
> > > > +++ b/include/sound/control.h
> > > > @@ -252,7 +252,7 @@ void snd_ctl_sync_vmaster(struct snd_kcontrol
> > > *kctl, bool hook_only);
> > > >   * Helper functions for jack-detection controls
> > > >   */
> > > >  struct snd_kcontrol *
> > > > -snd_kctl_jack_new(const char *name, int idx, void *private_data);
> > > > +snd_kctl_jack_new(const char *name, struct snd_card *card);
> > > >  void snd_kctl_jack_report(struct snd_card *card,
> > > >  			  struct snd_kcontrol *kctl, bool status);
> > > >
> > > > diff --git a/sound/core/ctljack.c b/sound/core/ctljack.c index
> > > > e4b38fb..b631996 100644
> > > > --- a/sound/core/ctljack.c
> > > > +++ b/sound/core/ctljack.c
> > > > @@ -31,15 +31,46 @@ static struct snd_kcontrol_new jack_detect_kctl
> = {
> > > >  	.get = jack_detect_kctl_get,
> > > >  };
> > > >
> > > > +static int get_available_index(struct snd_card *card, const char
> > > > +*name) {
> > > > +	struct snd_ctl_elem_id sid;
> > > > +
> > > > +	memset(&sid, 0, sizeof(sid));
> > > > +
> > > > +	sid.index = 0;
> > > > +	sid.iface = SNDRV_CTL_ELEM_IFACE_CARD;
> > > > +	strlcpy(sid.name, name, sizeof(sid.name));
> > > > +
> > > > +	while (snd_ctl_find_id(card, &sid))
> > > > +		sid.index++;
> > > > +
> > > > +	return sid.index;
> > > > +}
> > > > +
> > > > +static void jack_kctl_name_gen(char *name, const char *src_name,
> > > > +int
> > > > +size) {
> > > > +	size_t count = strlen(src_name);
> > > > +	bool need_cat = true;
> > > > +
> > > > +	/* remove redundant " Jack" from src_name */
> > > > +	if (count >= 5)
> > > > +		need_cat = strncmp(&src_name[count - 5], " Jack", 5) ? true :
> > > > +false;
> > > > +
> > > > +	snprintf(name, size, need_cat ? "%s Jack" : "%s", src_name);
> > > > +
> > > > +}
> > > > +
> > > >  struct snd_kcontrol *
> > > > -snd_kctl_jack_new(const char *name, int idx, void *private_data)
> > > > +snd_kctl_jack_new(const char *name, struct snd_card *card)
> > > >  {
> > > >  	struct snd_kcontrol *kctl;
> > > > -	kctl = snd_ctl_new1(&jack_detect_kctl, private_data);
> > > > +
> > > > +	kctl = snd_ctl_new1(&jack_detect_kctl, card);
> > >
> > > Why changing the private data?  Did it really work...?
> >
> > After this refactoring series, only jack.c:snd_jack_kctl_new() will
> > call this
> > snd_kctl_jack_new() with struct snd_card * passed in, so I changed it
> > here, to make it easier for reading.
> >
> > Here struct snd_card * will be cast to void * in snd_ctl_new1().
> >
> > Actually, I can keep it as before, then struct snd_card * will be cast
> > to void * in snd_kctl_jack_new().
> >
> > Seems no big difference with these two method? If you like, I can
> > change It back.
> 
> You break the bisectionability in your series.
> 
> Try to build and test at *each* commit whether it works as expected.
> Since snd_kctl_jack_new() is still called from hda_jack.c at this commit, it'll
> certainly crash when the jack is actually handled.
> Or, maybe it's even before that -- it may result in double jacks.
 
Thanks for pointing out this, cast codec to card is really a risk here, will change
it back.

> 
> Especially test with several kconfigs to build (with and without
> CONFIG_SND_HDA_INPUT_JACK and CONFIG_SND_JACK), and test with the
> actual HD-audio driver.

Um, I tested the building for each commit with, but not run for each. Will notice
it next time.

> 
> Keeping things working isn't an easy task, but it's often worthwhile.
> Once when you have done, you have idea how to manage a patch series.
 
That's true. Thanks for guiding patiently. :)

> 
> 
> Takashi