[ALSA] HDA: Enable chipset gcap usage

This patch removes hardcoded values for the number of streams supported
by the southbridge in most chipsets, and reads these values from the
chipset directly.  Most systems are hardwired for 4 streams in each
direction, but newer chipsets change that capability.
Signed-off-by: Tobin Davis <tdavis@dsl-only.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/hda/hda_intel.c

@@ -1708,12 +1708,13 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
 {
 	struct azx *chip;
 	int err;
+	unsigned short gcap;
 	static struct snd_device_ops ops = {
 		.dev_free = azx_dev_free,
 	};
 
 	*rchip = NULL;
-	
+
 	err = pci_enable_device(pci);
 	if (err < 0)
 		return err;
@@ -1775,25 +1776,40 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
 	pci_set_master(pci);
 	synchronize_irq(chip->irq);
 
-	switch (chip->driver_type) {
-	case AZX_DRIVER_ULI:
-		chip->playback_streams = ULI_NUM_PLAYBACK;
-		chip->capture_streams = ULI_NUM_CAPTURE;
-		chip->playback_index_offset = ULI_PLAYBACK_INDEX;
-		chip->capture_index_offset = ULI_CAPTURE_INDEX;
-		break;
-	case AZX_DRIVER_ATIHDMI:
-		chip->playback_streams = ATIHDMI_NUM_PLAYBACK;
-		chip->capture_streams = ATIHDMI_NUM_CAPTURE;
-		chip->playback_index_offset = ATIHDMI_PLAYBACK_INDEX;
-		chip->capture_index_offset = ATIHDMI_CAPTURE_INDEX;
-		break;
-	default:
-		chip->playback_streams = ICH6_NUM_PLAYBACK;
-		chip->capture_streams = ICH6_NUM_CAPTURE;
-		chip->playback_index_offset = ICH6_PLAYBACK_INDEX;
-		chip->capture_index_offset = ICH6_CAPTURE_INDEX;
-		break;
+	gcap = azx_readw(chip, GCAP);
+	snd_printdd("chipset global capabilities = 0x%x\n", gcap);
+
+	if (gcap) {
+		/* read number of streams from GCAP register instead of using
+		 * hardcoded value
+		 */
+		chip->playback_streams = (gcap & (0xF << 12)) >> 12;
+		chip->capture_streams = (gcap & (0xF << 8)) >> 8;
+		chip->playback_index_offset = (gcap & (0xF << 12)) >> 12;
+		chip->capture_index_offset = 0;
+	} else {
+		/* gcap didn't give any info, switching to old method */
+
+		switch (chip->driver_type) {
+		case AZX_DRIVER_ULI:
+			chip->playback_streams = ULI_NUM_PLAYBACK;
+			chip->capture_streams = ULI_NUM_CAPTURE;
+			chip->playback_index_offset = ULI_PLAYBACK_INDEX;
+			chip->capture_index_offset = ULI_CAPTURE_INDEX;
+			break;
+		case AZX_DRIVER_ATIHDMI:
+			chip->playback_streams = ATIHDMI_NUM_PLAYBACK;
+			chip->capture_streams = ATIHDMI_NUM_CAPTURE;
+			chip->playback_index_offset = ATIHDMI_PLAYBACK_INDEX;
+			chip->capture_index_offset = ATIHDMI_CAPTURE_INDEX;
+			break;
+		default:
+			chip->playback_streams = ICH6_NUM_PLAYBACK;
+			chip->capture_streams = ICH6_NUM_CAPTURE;
+			chip->playback_index_offset = ICH6_PLAYBACK_INDEX;
+			chip->capture_index_offset = ICH6_CAPTURE_INDEX;
+			break;
+		}
 	}
 	chip->num_streams = chip->playback_streams + chip->capture_streams;
 	chip->azx_dev = kcalloc(chip->num_streams, sizeof(*chip->azx_dev),