ASoC: topology: Select SND_DYNAMIC_MINORS
The indexes of the devices are described within the topology file, it is a
possibility that the topology encodes invalid indexes when DYNAMIC_MINORS
is not enabled in kernel:
#define SNDRV_MINOR_COMPRESS 2 /* 2 - 3 */
#define SNDRV_MINOR_HWDEP 4 /* 4 - 7 */
#define SNDRV_MINOR_RAWMIDI 8 /* 8 - 15 */
#define SNDRV_MINOR_PCM_PLAYBACK 16 /* 16 - 23 */
#define SNDRV_MINOR_PCM_CAPTURE 24 /* 24 - 31 */
If the topology assigns an index greater than 7 for PLAYBACK/CAPTURE PCM
then there will be minor number collision.
As an example:
card0 creates a capture PCM with index 10 -> minor = 34
card1 creates compress device with index 0 -> minor = 34
Card1 will fail to instantiate because the minor for the compress stream is
already taken.
To avoid seemingly mysterious issues with card creation, select the
DYNAMIC_MINORS when the topology is enabled.
The other option would be to try to do out of bound index checks in case of
DYNAMIC_MINOR is not enabled and do not even attempt to create the device
with failing the topology load.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210726182142.179604-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed