ALSA CVS update - Takashi Iwai <tiwai@suse.de>

ALSA<-OSS emulation
added fallback device selection for OSS mixer.

sound/core/oss/mixer_oss.c

@@ -872,7 +872,12 @@ static void mixer_slot_clear(snd_mixer_oss_slot_t *rslot)
 	rslot->number = idx;
 }
 
-static int snd_mixer_oss_build_input(snd_mixer_oss_t *mixer, struct snd_mixer_oss_assign_table *ptr, int ptr_allocated)
+/*
+ * build an OSS mixer element.
+ * ptr_allocated means the entry is dynamically allocated (change via proc file).
+ * when replace_old = 1, the old entry is replaced with the new one.
+ */
+static int snd_mixer_oss_build_input(snd_mixer_oss_t *mixer, struct snd_mixer_oss_assign_table *ptr, int ptr_allocated, int replace_old)
 {
 	struct slot slot;
 	struct slot *pslot;
@@ -880,6 +885,10 @@ static int snd_mixer_oss_build_input(snd_mixer_oss_t *mixer, struct snd_mixer_os
 	snd_mixer_oss_slot_t *rslot;
 	char str[64];	
 	
+	/* check if already assigned */
+	if (mixer->slots[ptr->oss_id].get_volume && ! replace_old)
+		return 0;
+
 	memset(&slot, 0, sizeof(slot));
 	if (snd_mixer_oss_build_test(mixer, &slot, ptr->name, ptr->index,
 				     SNDRV_MIXER_OSS_ITEM_GLOBAL))
@@ -1084,7 +1093,7 @@ static void snd_mixer_oss_proc_write(snd_info_entry_t *entry,
 			goto __unlock;
 		}
 		tbl->index = idx;
-		if (snd_mixer_oss_build_input(mixer, tbl, 1) <= 0) {
+		if (snd_mixer_oss_build_input(mixer, tbl, 1, 1) <= 0) {
 			kfree(tbl->name);
 			kfree(tbl);
 		}
@@ -1127,9 +1136,11 @@ static void snd_mixer_oss_build(snd_mixer_oss_t *mixer)
 {
 	static struct snd_mixer_oss_assign_table table[] = {
 		{ SOUND_MIXER_VOLUME, 	"Master",		0 },
+		{ SOUND_MIXER_VOLUME, 	"Front",		0 }, /* fallback */
 		{ SOUND_MIXER_BASS,	"Tone Control - Bass",	0 },
 		{ SOUND_MIXER_TREBLE,	"Tone Control - Treble", 0 },
 		{ SOUND_MIXER_SYNTH,	"Synth",		0 },
+		{ SOUND_MIXER_SYNTH,	"FM",			0 }, /* fallback */
 		{ SOUND_MIXER_PCM,	"PCM",			0 },
 		{ SOUND_MIXER_SPEAKER,	"PC Speaker", 		0 },
 		{ SOUND_MIXER_LINE,	"Line", 		0 },
@@ -1137,6 +1148,7 @@ static void snd_mixer_oss_build(snd_mixer_oss_t *mixer)
 		{ SOUND_MIXER_CD,	"CD", 			0 },
 		{ SOUND_MIXER_IMIX,	"Monitor Mix", 		0 },
 		{ SOUND_MIXER_ALTPCM,	"PCM",			1 },
+		{ SOUND_MIXER_ALTPCM,	"Wave",			0 }, /* fallback */
 		{ SOUND_MIXER_RECLEV,	"-- nothing --",	0 },
 		{ SOUND_MIXER_IGAIN,	"Capture",		0 },
 		{ SOUND_MIXER_OGAIN,	"Playback",		0 },
@@ -1152,15 +1164,10 @@ static void snd_mixer_oss_build(snd_mixer_oss_t *mixer)
 		{ SOUND_MIXER_RADIO,	"Radio",		0 },
 		{ SOUND_MIXER_MONITOR,	"Monitor",		0 }
 	};
-	static struct snd_mixer_oss_assign_table fm_table = {
-		SOUND_MIXER_SYNTH,	"FM",			0
-	};
 	unsigned int idx;
 	
 	for (idx = 0; idx < sizeof(table) / sizeof(struct snd_mixer_oss_assign_table); idx++)
-		snd_mixer_oss_build_input(mixer, &table[idx], 0);
-	if (mixer->slots[SOUND_MIXER_SYNTH].get_volume == NULL)
-		snd_mixer_oss_build_input(mixer, &fm_table, 0);
+		snd_mixer_oss_build_input(mixer, &table[idx], 0, 0);
 	if (mixer->mask_recsrc) {
 		mixer->get_recsrc = snd_mixer_oss_get_recsrc2;
 		mixer->put_recsrc = snd_mixer_oss_put_recsrc2;