ALSA: hda_controller: Separate stream_tag for input and output streams.

Implemented separate stream_tag assignment for input and output streams.
According to hda specification stream tag must be unique throughout the
input streams group, however an output stream might use a stream tag
which is already in use by an input stream. This change is necessary
to support HW which provides a total of more than 15 stream DMA engines
which with legacy implementation causes an overflow on SDxCTL.STRM
field (and the whole SDxCTL register) and as a result usage of
Reserved value 0 in the SDxCTL.STRM field which confuses HDA controller.

Signed-off-by: Rafal Redzimski <rafal.f.redzimski@intel.com>
Signed-off-by: Jayachandran B <jayachandran.b@intel.com>
Signed-off-by: Libin Yang <libin.yang@intel.com>
Reviewed-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_controller.c

@@ -1922,10 +1922,18 @@ int azx_mixer_create(struct azx *chip)
 EXPORT_SYMBOL_GPL(azx_mixer_create);
 
 
+static bool is_input_stream(struct azx *chip, unsigned char index)
+{
+	return (index >= chip->capture_index_offset &&
+		index < chip->capture_index_offset + chip->capture_streams);
+}
+
 /* initialize SD streams */
 int azx_init_stream(struct azx *chip)
 {
 	int i;
+	int in_stream_tag = 0;
+	int out_stream_tag = 0;
 
 	/* initialize each stream (aka device)
 	 * assign the starting bdl address to each stream (device)
@@ -1938,9 +1946,21 @@ int azx_init_stream(struct azx *chip)
 		azx_dev->sd_addr = chip->remap_addr + (0x20 * i + 0x80);
 		/* int mask: SDI0=0x01, SDI1=0x02, ... SDO3=0x80 */
 		azx_dev->sd_int_sta_mask = 1 << i;
-		/* stream tag: must be non-zero and unique */
 		azx_dev->index = i;
-		azx_dev->stream_tag = i + 1;
+
+		/* stream tag must be unique throughout
+		 * the stream direction group,
+		 * valid values 1...15
+		 * use separate stream tag if the flag
+		 * AZX_DCAPS_SEPARATE_STREAM_TAG is used
+		 */
+		if (chip->driver_caps & AZX_DCAPS_SEPARATE_STREAM_TAG)
+			azx_dev->stream_tag =
+				is_input_stream(chip, i) ?
+				++in_stream_tag :
+				++out_stream_tag;
+		else
+			azx_dev->stream_tag = i + 1;
 	}
 
 	return 0;

sound/pci/hda/hda_priv.h

@@ -171,6 +171,7 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2, SDO3 };
 #define AZX_DCAPS_I915_POWERWELL (1 << 27)	/* HSW i915 powerwell support */
 #define AZX_DCAPS_CORBRP_SELF_CLEAR (1 << 28)	/* CORBRP clears itself after reset */
 #define AZX_DCAPS_NO_MSI64      (1 << 29)	/* Stick to 32-bit MSIs */
+#define AZX_DCAPS_SEPARATE_STREAM_TAG	(1 << 30) /* capture and playback use separate stream tag */
 
 enum {
 	AZX_SNOOP_TYPE_NONE ,