[alsa-devel] [PATCH - alsa-lib 1/1] Change card/pid get functions to return -ENOSYS if the kernel is too old

[Martin Koegler]

On Fri, Apr 01, 2016 at 01:33:50PM -0400, Adam Goode wrote:
> When trying to get the pid or card of a client, the get functions will
> return -1 if there is no pid or card for a client. Clients have zero or
> one of these, so -1 is correct for these cases. But we also need to detect
> the case where the kernel cannot tell us if there is a card or pid, so
> that userspace can fallback to probing this information in the old way.

Its a pity, that alsa-lib 1.1.1 has just been released, which just returns -1.
If the time between releases is really about 2 kernel releases, you will very likely
have to cope with the old API for some time.

Regards,
Martin