ALSA: hda - Fix mute sound with STAC9227/9228 codecs

On FSC laptops, the sound gets muted gradually when the volume is chnaged.
This is due to the wrong volume-knob widget setup.  The delta bit (bit 7)
shouldn't be set for these devices.

This patch adds a new quirk to set the value 0x7f to the widget 0x24
instead of 0xff.

Reference: Novell bnc#546006
	http://bugzilla.novell.com/show_bug.cgi?id=546006Signed-off-by: Takashi Iwai <tiwai@suse.de>

Documentation/sound/alsa/HD-Audio-Models.txt

@@ -359,6 +359,7 @@ STAC9227/9228/9229/927x
   5stack-no-fp	D965 5stack without front panel
   dell-3stack	Dell Dimension E520
   dell-bios	Fixes with Dell BIOS setup
+  volknob	Fixes with volume-knob widget 0x24
   auto		BIOS setup (default)
 
 STAC92HD71B*

sound/pci/hda/patch_sigmatel.c

@@ -158,6 +158,7 @@ enum {
 	STAC_D965_5ST_NO_FP,
 	STAC_DELL_3ST,
 	STAC_DELL_BIOS,
+	STAC_927X_VOLKNOB,
 	STAC_927X_MODELS
 };
 
@@ -915,6 +916,14 @@ static struct hda_verb stac927x_core_init[] = {
 	{}
 };
 
+static struct hda_verb stac927x_volknob_core_init[] = {
+	/* don't set delta bit */
+	{0x24, AC_VERB_SET_VOLUME_KNOB_CONTROL, 0x7f},
+	/* enable analog pc beep path */
+	{0x01, AC_VERB_SET_DIGI_CONVERT_2, 1 << 5},
+	{}
+};
+
 static struct hda_verb stac9205_core_init[] = {
 	/* set master volume and direct control */	
 	{ 0x24, AC_VERB_SET_VOLUME_KNOB_CONTROL, 0xff},
@@ -1999,6 +2008,7 @@ static unsigned int *stac927x_brd_tbl[STAC_927X_MODELS] = {
 	[STAC_D965_5ST_NO_FP]  = d965_5st_no_fp_pin_configs,
 	[STAC_DELL_3ST]  = dell_3st_pin_configs,
 	[STAC_DELL_BIOS] = NULL,
+	[STAC_927X_VOLKNOB] = NULL,
 };
 
 static const char *stac927x_models[STAC_927X_MODELS] = {
@@ -2010,6 +2020,7 @@ static const char *stac927x_models[STAC_927X_MODELS] = {
 	[STAC_D965_5ST_NO_FP]	= "5stack-no-fp",
 	[STAC_DELL_3ST]		= "dell-3stack",
 	[STAC_DELL_BIOS]	= "dell-bios",
+	[STAC_927X_VOLKNOB]	= "volknob",
 };
 
 static struct snd_pci_quirk stac927x_cfg_tbl[] = {
@@ -2045,6 +2056,8 @@ static struct snd_pci_quirk stac927x_cfg_tbl[] = {
 			   "Intel D965", STAC_D965_5ST),
 	SND_PCI_QUIRK_MASK(PCI_VENDOR_ID_INTEL, 0xff00, 0x2500,
 			   "Intel D965", STAC_D965_5ST),
+	/* volume-knob fixes */
+	SND_PCI_QUIRK_VENDOR(0x10cf, "FSC", STAC_927X_VOLKNOB),
 	{} /* terminator */
 };
 
@@ -5616,6 +5629,10 @@ static int patch_stac927x(struct hda_codec *codec)
 		spec->dmux_nids = stac927x_dmux_nids;
 		spec->num_dmuxes = ARRAY_SIZE(stac927x_dmux_nids);
 		break;
+	case STAC_927X_VOLKNOB:
+		spec->num_dmics = 0;
+		spec->init = stac927x_volknob_core_init;
+		break;
 	default:
 		spec->num_dmics = 0;
 		spec->init = stac927x_core_init;