ALSA: ac97 - Enable mono-out on ALC203 codec as default

Use pin 37 for mono-out as default on ALC203.
Reported-by: george pee <georgepee@gmail.com>
Tested-by: george pee <georgepee@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/ac97/ac97_codec.c

@@ -122,7 +122,7 @@ static const struct ac97_codec_id snd_ac97_codec_ids[] = {
 { 0x414c4740, 0xfffffff0, "ALC202",		NULL,		NULL },
 { 0x414c4750, 0xfffffff0, "ALC250",		NULL,		NULL },
 { 0x414c4760, 0xfffffff0, "ALC655",		patch_alc655,	NULL },
-{ 0x414c4770, 0xfffffff0, "ALC203",		NULL,		NULL },
+{ 0x414c4770, 0xfffffff0, "ALC203",		patch_alc203,	NULL },
 { 0x414c4781, 0xffffffff, "ALC658D",		NULL,	NULL }, /* already patched */
 { 0x414c4780, 0xfffffff0, "ALC658",		patch_alc655,	NULL },
 { 0x414c4790, 0xfffffff0, "ALC850",		patch_alc850,	NULL },

sound/pci/ac97/ac97_patch.c

@@ -2560,6 +2560,14 @@ static int patch_ad1986(struct snd_ac97 * ac97)
 	return 0;
 }
 
+/*
+ * realtek ALC203: use mono-out for pin 37
+ */
+static int patch_alc203(struct snd_ac97 *ac97)
+{
+	snd_ac97_update_bits(ac97, 0x7a, 0x400, 0x400);
+	return 0;
+}
 
 /*
  * realtek ALC65x/850 codecs