[alsa-devel] [PATCH] ALSA: jack: create jack kcontrols for every jack input device

[Takashi Iwai]

At Thu, 19 Mar 2015 13:53:17 +0000,
Jie, Yang wrote:
> 
> > -----Original Message-----
> > From: Takashi Iwai [mailto:tiwai at suse.de]
> > Sent: Thursday, March 19, 2015 6:51 PM
> > To: Jie, Yang
> > Cc: perex at perex.cz; broonie at kernel.org; alsa-devel at alsa-project.org;
> > Girdwood, Liam R; Liam Girdwood
> > Subject: Re: [PATCH] ALSA: jack: create jack kcontrols for every jack input
> > device
> > 
> > At Thu, 19 Mar 2015 16:40:18 +0800,
> > Jie Yang wrote:
> > >
> > > From: Liam Girdwood <liam.r.girdwood at linux.intel.com>
> > >
> > > Currently the ALSA jack core registers only input devices for each
> > > jack registered. These jack input devices are not readable by
> > > userspace devices that run as non root.
> > >
> > > This patch adds support for additionally registering jack kcontrol
> > > devices for every input jack registered. This allows non root
> > > userspace to read jack status.
> > >
> > > Signed-off-by: Liam Girdwood <liam.r.girdwood at linux.intel.com>
> > > Modified-by: Jie Yang <yang.jie at intel.com>
> > > Signed-off-by: Jie Yang <yang.jie at intel.com>
> > > Reveiwed-by: Mark Brown <broonie at kernel.org>
> > > ---
> > >  include/sound/control.h |  2 ++
> > >  include/sound/jack.h    |  2 ++
> > >  sound/core/jack.c       | 89
> > +++++++++++++++++++++++++++++++++++++++++++++++--
> > >  3 files changed, 91 insertions(+), 2 deletions(-)  mode change 100644
> > > => 100755 sound/core/jack.c
> > >
> > > diff --git a/include/sound/control.h b/include/sound/control.h index
> > > 75f3054..023b70a 100644
> > > --- a/include/sound/control.h
> > > +++ b/include/sound/control.h
> > > @@ -66,6 +66,7 @@ struct snd_kcontrol_volatile {
> > >
> > >  struct snd_kcontrol {
> > >  	struct list_head list;		/* list of controls */
> > > +	struct list_head jack_list;		/* list of controls belong to
> > the same jack*/
> > >  	struct snd_ctl_elem_id id;
> > >  	unsigned int count;		/* count of same elements */
> > >  	snd_kcontrol_info_t *info;
> > > @@ -75,6 +76,7 @@ struct snd_kcontrol {
> > >  		snd_kcontrol_tlv_rw_t *c;
> > >  		const unsigned int *p;
> > >  	} tlv;
> > > +	unsigned int jack_bit_idx;	/*the corresponding jack type bit
> > index */
> > >  	unsigned long private_value;
> > >  	void *private_data;
> > >  	void (*private_free)(struct snd_kcontrol *kcontrol);
> > 
> > NAK for these additions.  There must be a way to implement without such
> > *generic* additions in kcontrol.
> [Keyon] how about define another struct jack_kcontrol in jack.h like below?
> 
> struct jack_kcontrol {
> 	struct snd_kcontrol * kctl;
> 	struct list_head jack_list;		/* list of controls belong to
>  the same jack*/
> 	unsigned int jack_bit_idx;	/*the corresponding jack type bit
>  index */
> }

Yes, and point it from kctl->private_data.


Takashi