ALSA: hda_intel: activate COMBO mode for Intel client chipsets

This patch activates the COMBO position_fix for recent Intel client chipsets.
COMBO mode is the recommended setting for Intel chipsets and eliminates HD
audio warnings in dmesg.  This patch has been tested on Lynx Point, Panther
Point, and Cougar Pont.
Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_intel.c

@@ -535,6 +535,7 @@ enum {
 #define AZX_DCAPS_BUFSIZE	(1 << 21)	/* no buffer size alignment */
 #define AZX_DCAPS_ALIGN_BUFSIZE	(1 << 22)	/* buffer size alignment */
 #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23)	/* BDLE in 4k boundary */
+#define AZX_DCAPS_POSFIX_COMBO  (1 << 24)	/* Use COMBO as default */
 
 /* quirks for ATI SB / AMD Hudson */
 #define AZX_DCAPS_PRESET_ATI_SB \
@@ -2728,6 +2729,10 @@ static int __devinit check_position_fix(struct azx *chip, int fix)
 		snd_printd(SFX "Using LPIB position fix\n");
 		return POS_FIX_LPIB;
 	}
+	if (chip->driver_caps & AZX_DCAPS_POSFIX_COMBO) {
+		snd_printd(SFX "Using COMBO position fix\n");
+		return POS_FIX_COMBO;
+	}
 	return POS_FIX_AUTO;
 }
 
@@ -3240,7 +3245,7 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = {
 	/* CPT */
 	{ PCI_DEVICE(0x8086, 0x1c20),
 	  .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP |
-	  AZX_DCAPS_BUFSIZE },
+	  AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO },
 	/* PBG */
 	{ PCI_DEVICE(0x8086, 0x1d20),
 	  .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP |
@@ -3248,11 +3253,11 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = {
 	/* Panther Point */
 	{ PCI_DEVICE(0x8086, 0x1e20),
 	  .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP |
-	  AZX_DCAPS_BUFSIZE},
+	  AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO },
 	/* Lynx Point */
 	{ PCI_DEVICE(0x8086, 0x8c20),
 	  .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_SCH_SNOOP |
-	  AZX_DCAPS_BUFSIZE},
+	  AZX_DCAPS_BUFSIZE | AZX_DCAPS_POSFIX_COMBO },
 	/* SCH */
 	{ PCI_DEVICE(0x8086, 0x811b),
 	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_SCH_SNOOP |