[alsa-devel] [PATCH - alsa-lib 1/1] Introduce snd_seq_client_info_get_card_number, for getting the card number of a seq client on recent kernels

[Takashi Iwai]

At Fri, 05 Jun 2015 08:50:45 +0200,
Clemens Ladisch wrote:
> 
> Adam Goode wrote:
> >  /**
> > + * \brief Get the card number of a client_info container
> > + * \param info client_info container
> > + * \return the card number, -1 if no card associated with this client, or -ENOSYS if the
> > + *         kernel does not support reporting this field
> > + */
> 
> -1 is used as an out-of-range value when enumerating cards.  However,
> I don't think this convention can be applied here, because the return
> value is also used for error codes, and -1 would correspond to -EPERM.
> 
> Squashing all error codes into -1 is not a good idea, so I think the
> value -1 should be converted into an appropriate error code, probably
> -ENXIO.

Agreed.

Also, please don't include irrelevant changes in configure.ac.


thanks,

Takashi