[alsa-devel] hdspm.c - confused about SNDRV_HDSPM_IOCTL_GET_[CONFIG|STATUS]

Takashi Iwai tiwai at suse.de
Wed May 18 18:17:37 CEST 2011

At Sun, 15 May 2011 18:31:47 +0200,
Jörn Nettingsmeier wrote:
> hi *!
> i'm trying to extend hdspconf to work with the rme hdspm madi card, and 
> got confused over the snd_hdspm_hwdep_ioctl:
> apparently, the hdspm.c driver differentiates between settable controls 
> (CONFIG) and non-settable status indicators (STATUS), unlike the earlier 
> hdspm.c.
> however, usage seems a bit inconsistent:
> struct hdspm_config contains a member madi_sync_check, which is 
> apparently never set.

This was also in the older version, and the structure wasn't changed
for compatibility reason.

> instead, struct hdspm_status card_specific.sync_madi is used, same for 
> tco and sync in.
> but there is a wordclock_sync_check in struct hdspm_config which is in use.
> am i guessing right that the latter is somewhat deprecated and that i 
> should be taking all status values from struct hdspm_status instead?

Well, consider GET_STATUS as a kind of extended attributes.


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