[ALSA] Fix substream selection in PCM and rawmidi

The PCM and rawmidi substreams can be selected explicitly by opening control handle and set via *_PREFER_SUBDEVICE ioctl. But, when multiple controls are opened, the driver gets confused. The patch fixes the initialization of prefer_*_subdevice and the check of multiple controls. The first set subdevice is picked up as the valid one. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@suse.cz>
nomis · Sep 23, 2006 · 2529bba · 2529bba
1 parent f03d68f
commit 2529bba
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Showing 3 changed files with 6 additions and 2 deletions.
diff --git a/sound/core/control.c b/sound/core/control.c
@@ -75,6 +75,8 @@ static int snd_ctl_open(struct inode *inode, struct file *file)
 	init_waitqueue_head(&ctl->change_sleep);
 	spin_lock_init(&ctl->read_lock);
 	ctl->card = card;
+	ctl->prefer_pcm_subdevice = -1;
+	ctl->prefer_rawmidi_subdevice = -1;
 	ctl->pid = current->pid;
 	file->private_data = ctl;
 	write_lock_irqsave(&card->ctl_files_rwlock, flags);

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
@@ -792,7 +792,8 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 		kctl = snd_ctl_file(list);
 		if (kctl->pid == current->pid) {
 			prefer_subdevice = kctl->prefer_pcm_subdevice;
-			break;
+			if (prefer_subdevice != -1)
+				break;
 		}
 	}
 	up_read(&card->controls_rwsem);

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
@@ -430,7 +430,8 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
 			kctl = snd_ctl_file(list);
 			if (kctl->pid == current->pid) {
 				subdevice = kctl->prefer_rawmidi_subdevice;
-				break;
+				if (subdevice != -1)
+					break;
 			}
 		}
 		up_read(&card->controls_rwsem);