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ALSA: core: Add snd_device_get_state() helper 

A new small helper to get the current state of the device registration
for the given object.  It'll be used for USB-audio driver to check the
delayed device registrations.

Link: https://lore.kernel.org/r/20200323170643.19181-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2020-03-23 18:06:42 +01:00
parent 55f7326170
commit c208a53350
2 changed files with 22 additions and 0 deletions
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1
include/sound/core.h
View File

@ -266,6 +266,7 @@ void snd_device_disconnect(struct snd_card *card, void *device_data);
void snd_device_disconnect_all(struct snd_card *card);
void snd_device_free(struct snd_card *card, void *device_data);
void snd_device_free_all(struct snd_card *card);
int snd_device_get_state(struct snd_card *card, void *device_data);
/* isadma.c */

21
sound/core/device.c
View File

@ -237,3 +237,24 @@ void snd_device_free_all(struct snd_card *card)
list_for_each_entry_safe_reverse(dev, next, &card->devices, list)
__snd_device_free(dev);
}
/**
* snd_device_get_state - Get the current state of the given device
* @card: the card instance
* @device_data: the data pointer to release
*
* Returns the current state of the given device object. For the valid
* device, either @SNDRV_DEV_BUILD, @SNDRV_DEV_REGISTERED or
* @SNDRV_DEV_DISCONNECTED is returned.
* Or for a non-existing device, -1 is returned as an error.
*/
int snd_device_get_state(struct snd_card *card, void *device_data)
{
struct snd_device *dev;
dev = look_for_dev(card, device_data);
if (dev)
return dev->state;
return -1;
}
EXPORT_SYMBOL_GPL(snd_device_get_state);