[alsa-devel] [PATCH 8/31] HDA patch_via.c: Change VT1708S & VT1702 hp mode controls

[Li Bo]

On Wed, Oct 7, 2009 at 2:03 AM, Takashi Iwai <tiwai at suse.de> wrote:
> At Wed, 7 Oct 2009 01:42:50 +0800,
> Li Bo wrote:
>>
>> On Tue, Oct 6, 2009 at 11:55 PM, Li Bo <liboat at gmail.com> wrote:
>> > On Tue, Oct 6, 2009 at 1:47 PM, Takashi Iwai <tiwai at suse.de> wrote:
>> >> At Tue, 6 Oct 2009 12:44:28 +0800,
>> >> Li Bo wrote:
>> >>>
>> >>> Hi, Takashi
>> >>>   When independent hp switches from
>> >>>           on -> off: hp volume/switch is deactivated
>> >>>           off -> hp volume switch  is activated
>> >>>   These 2 actions are one-shot setup, so we put "need reboot" to remind user
>> >>>   that hp volume/switch update will only take effect after reboot.
>> >>
>> >> First off, you don't have to "reboot" at all :)
>> >>
>> >
>> > I also want to kick that "reboot" off:)
>> >
>> >> And, the activation/deactivation can be done on the fly, so it's no
>> >> more "one-shot" action (if implemented properly).
>> >>
>> >>
>> >> Takashi
>> >>
>> >
>> > You mean just act/deact on via_independent_hp_put? I'll try and update this,
>> > thank you!
>> >
>> Sorry I don't know how to activate/deactivate on the fly. I toggle access'
>> SNDRV_CTL_ELEM_ACCESS_INACTIVE bit in via_independent_hp_put, but
>> in alsamixer it cannot reflect the change unless restart it. Please
>> give some help.
>
> You simply need to notify the control elements you changed via
> snd_ctl_notify().
> Then the mixer app will update the status as well.
>
>
> Takashi
>

I add snd_ctl_notify after access update, but test with results that:
  - alsamixer (v1.0.21) will gray/de-grayed the control only after
restart the application
  - gnome-volume-control will just ignore the access bit and display
the control as usual.
Maybe we have to backward to snd_ctl_remove implementation.