ALSA: control: Provide a helper to look for the preferred subdevice

Instead of open-coding the search over the control file loop, provide
a helper function for the preferred subdevice assigned to the current
process.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 9 insertions, 2 deletions

diff --git a/include/sound/control.h b/include/sound/control.h
index 042613938a1d..75f3054023f7 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -93,12 +93,17 @@ struct snd_kctl_event {
 
 struct pid;
 
+enum {
+        SND_CTL_SUBDEV_PCM,
+        SND_CTL_SUBDEV_RAWMIDI,
+        SND_CTL_SUBDEV_ITEMS,
+};
+
 struct snd_ctl_file {
         struct list_head list;          /* list of all control files */
         struct snd_card *card;
         struct pid *pid;
-        int prefer_pcm_subdevice;
-        int prefer_rawmidi_subdevice;
+        int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
         wait_queue_head_t change_sleep;
         spinlock_t read_lock;
         struct fasync_struct *fasync;
@@ -138,6 +143,8 @@ int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 #define snd_ctl_unregister_ioctl_compat(fcn)
 #endif
 
+int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
+
 static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 {
         return id->numid - kctl->id.numid;