[alsa-devel] Some questions about userspace control elements

[Takashi Sakamoto]

On Feb 8 2014 00:45, Clemens Ladisch wrote:
> Takashi Sakamoto wrote:
>> On Feb 6 2015 18:38, Clemens Ladisch wrote:
>>> The owner field is used because there is no other field to set the
>>> count.
>>
>> No. In SNDRV_CTL_IOCTL_ELEM_ADD ioctl, struct snd_ctl_elem_info.count
>> has the number of elements in this control, there it's an abuse of
>> member unrelated to the count.
> 
> That is a different count.
> 
> struct snd_ctl_elem_info.count allows a control to have multiple values.
> For example, a stereo volume control has two values.
> 
> kctl.count creates multiple controls.

Oh, I confused these two 'count's... I'm OK that the count member in
struct snd_kcontrol means the number of controls (elements) with the
same type, and the count member in struct snd_ctl_elem_info means the
number of values in a controls, then the event occurs every controls,
not for values.


Thanks

Takashi Sakamoto