[alsa-devel] [alsa-lib][PATCH 0/5] ctl: support extra information for user-defined element set

[Takashi Iwai]

On Wed, 29 Jun 2016 15:42:58 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> This patchset adds support extra information to the type-specific for
> user-defined element set. Currently, 'dimension' is such an extra
> information.
> 
> In ALSA kernel/userspace interface, information to an element is described
> in this structure.
> 
> struct snd_ctl_elem_info {
>     struct snd_ctl_elem_id id;
>     unsigned int access;
>     unsigned int count;
>     pid_t owner;
>     union value;
> 
>     union dimen;
>     unsigned char reserved[64 - 4 * sizeof(unsigned short)];
> };
> 
> This structure includes reserved fields, thus it's possible to add
> more fields for future extension.
> 
> Currently, APIs to add user-defined element set don't support such extra
> fields. Meanwhile, supporting just the dimension field is not good as
> stable library APIs.
> 
> This patchset changes prototype of the APIs with 'snd_ctl_elem_info_t'
> instead of adding more parameters. Callers are expected to fill the parameter
> with identification information and the extra information.

Applied, thanks.

But at the next time, try to avoid changing the API functions you
added.  They must not be changed once when published, in general.


Takashi