alsactl: info - handle situations when devices are not available in k…

…ernel

The kernel returns ENOTTY error in this case. Do nothing for this error code.

Closes: #287
Signed-off-by: Jaroslav Kysela <[email protected]>

alsactl/info.c

@@ -35,6 +35,8 @@ static int pcm_device_list(snd_ctl_t *ctl, snd_pcm_stream_t stream, bool *first)
 	streamfirst = true;
 	while (1) {
 		if ((err = snd_ctl_pcm_next_device(ctl, &dev)) < 0) {
+			if (err == ENOTTY)	/* no kernel support */
+				return 0;
 			error("snd_ctl_pcm_next_device: %s", snd_strerror(err));
 			return err;
 		}
@@ -102,6 +104,8 @@ static int rawmidi_device_list(snd_ctl_t *ctl, snd_rawmidi_stream_t stream, bool
 	streamfirst = true;
 	while (1) {
 		if ((err = snd_ctl_rawmidi_next_device(ctl, &dev)) < 0) {
+			if (err == ENOTTY)	/* no kernel support */
+				return 0;
 			error("snd_ctl_rawmidi_next_device: %s", snd_strerror(err));
 			return err;
 		}
@@ -159,7 +163,9 @@ static int hwdep_device_list(snd_ctl_t *ctl)
 	first = true;
 	while (1) {
 		if ((err = snd_ctl_hwdep_next_device(ctl, &dev)) < 0) {
-			error("snd_ctl_pcm_next_device");
+			if (err == ENOTTY)	/* no kernel support */
+				return 0;
+			error("snd_ctl_pcm_next_device: %s", snd_strerror(err));
 			return err;
 		}
 		if (dev < 0)