[PATCH 0/4] multi-channel HDMI audio support

[PATCH 0/4] multi-channel HDMI audio support

[Wu Fengguang]

Hi Takashi,

This patchset attempts to support multi-channel HDMI audio.

It contains two basic operations:

- setup the CA(channel-allocation) byte in the audio infoframe
- setup the converter channel to HDMI slot mapping

Please read patch 3 for more detailed descriptions:

	[PATCH 1/4] hda: make standalone hdmi_fill_audio_infoframe()                               
	[PATCH 2/4] hda: make global snd_print_channel_allocation()                       
	[PATCH 3/4] hda: HDMI channel allocations for audio infoframe                               
	[PATCH 4/4] hda: HDMI channel mapping cleanups                                               

The current implementation only does minimal works that ensure multi-channel
audio playing out. However the wrong speakers may be selected. We could
elaborate the framework/policy if it proves to be a problem.

Thank you,
Fengguang
-- 

[PATCH 1/4] hda: make standalone hdmi_fill_audio_infoframe()

[Wu Fengguang]

[-- Attachment #1: alsa-infoframe-cleanup.patch --]
[-- Type: text/plain, Size: 1418 bytes --]

code refactor: make a standalone function hdmi_fill_audio_infoframe().

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
---
 sound/pci/hda/patch_intelhdmi.c |   25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

--- sound-2.6.orig/sound/pci/hda/patch_intelhdmi.c
+++ sound-2.6/sound/pci/hda/patch_intelhdmi.c
@@ -246,24 +246,31 @@ static void hdmi_clear_dip_buffers(struc
 #endif
 }
 
+static void hdmi_fill_audio_infoframe(struct hda_codec *codec,
+					struct hdmi_audio_infoframe *ai)
+{
+	u8 *params = (u8 *)ai;
+	int i;
+
+	hdmi_debug_dip_size(codec);
+	hdmi_clear_dip_buffers(codec); /* be paranoid */
+
+	hdmi_set_dip_index(codec, PIN_NID, 0x0, 0x0);
+	for (i = 0; i < sizeof(ai); i++)
+		hdmi_write_dip_byte(codec, PIN_NID, params[i]);
+}
+
 static void hdmi_setup_audio_infoframe(struct hda_codec *codec,
 					struct snd_pcm_substream *substream)
 {
-	struct hdmi_audio_infoframe audio_infoframe = {
+	struct hdmi_audio_infoframe ai = {
 		.type		= 0x84,
 		.ver		= 0x01,
 		.len		= 0x0a,
 		.CC02_CT47	= substream->runtime->channels - 1,
 	};
-	u8 *params = (u8 *)&audio_infoframe;
-	int i;
-
-	hdmi_debug_dip_size(codec);
-	hdmi_clear_dip_buffers(codec); /* be paranoid */
 
-	hdmi_set_dip_index(codec, PIN_NID, 0x0, 0x0);
-	for (i = 0; i < sizeof(audio_infoframe); i++)
-		hdmi_write_dip_byte(codec, PIN_NID, params[i]);
+	hdmi_fill_audio_infoframe(codec, &ai);
 }
 
 

-- 

[PATCH 2/4] hda: make global snd_print_channel_allocation()

[Wu Fengguang]

[-- Attachment #1: alsa-global-print-ca.patch --]
[-- Type: text/plain, Size: 2585 bytes --]

code refactor: make a global function snd_print_channel_allocation().

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
---
 sound/pci/hda/hda_eld.c   |   11 +++++------
 sound/pci/hda/hda_local.h |    3 +++
 2 files changed, 8 insertions(+), 6 deletions(-)

--- sound-2.6.orig/sound/pci/hda/hda_eld.c
+++ sound-2.6/sound/pci/hda/hda_eld.c
@@ -407,8 +407,7 @@ static void hdmi_show_short_audio_desc(s
 		printk(KERN_INFO "profile: %d\n", a->profile);
 }
 
-#define HDMI_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80
-static void hdmi_print_channel_allocation(int spk_alloc, char *buf, int buflen)
+void snd_print_channel_allocation(int spk_alloc, char *buf, int buflen)
 {
 	int i, j;
 
@@ -425,7 +424,7 @@ static void hdmi_print_channel_allocatio
 void snd_hdmi_show_eld(struct sink_eld *e)
 {
 	int i;
-	char buf[HDMI_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
 
 	printk(KERN_INFO "ELD buffer size  is %d\n", e->eld_size);
 	printk(KERN_INFO "ELD baseline len is %d*4\n", e->baseline_len);
@@ -446,7 +445,7 @@ void snd_hdmi_show_eld(struct sink_eld *
 				eld_connection_type_names[e->conn_type]);
 	printk(KERN_INFO "monitor name     is %s\n", e->monitor_name);
 
-	hdmi_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+	snd_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
 	printk(KERN_INFO "speaker allocations: (0x%x)%s\n", e->spk_alloc, buf);
 
 	for (i = 0; i < e->sad_count; i++)
@@ -484,7 +483,7 @@ static void hdmi_print_eld_info(struct s
 				struct snd_info_buffer *buffer)
 {
 	struct sink_eld *e = entry->private_data;
-	char buf[HDMI_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
 	int i;
 
 	snd_iprintf(buffer, "monitor name\t\t%s\n", e->monitor_name);
@@ -501,7 +500,7 @@ static void hdmi_print_eld_info(struct s
 	snd_iprintf(buffer, "support_ai\t\t%d\n", e->support_ai);
 	snd_iprintf(buffer, "audio_sync_delay\t%d\n", e->aud_synch_delay);
 
-	hdmi_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+	snd_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
 	snd_iprintf(buffer, "speakers\t\t[0x%x] %s\n", e->spk_alloc, buf);
 
 	snd_iprintf(buffer, "sad_count\t\t%d\n", e->sad_count);
--- sound-2.6.orig/sound/pci/hda/hda_local.h
+++ sound-2.6/sound/pci/hda/hda_local.h
@@ -493,4 +493,7 @@ inline int snd_hda_eld_proc_new(struct h
 }
 #endif
 
+#define SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80
+void snd_print_channel_allocation(int spk_alloc, char *buf, int buflen);
+
 #endif /* __SOUND_HDA_LOCAL_H */

-- 

[PATCH 3/4] hda: HDMI channel allocations for audio infoframe

[Wu Fengguang]

[-- Attachment #1: alsa-speakers.patch --]
[-- Type: text/plain, Size: 10117 bytes --]

To play a 3+ channels LPCM/DSD stream via HDMI,

	- HDMI sink must tell HDMI source about its speaker placements
	  (via ELD, speaker-allocation field)
	- HDMI source must tell the HDMI sink about channel allocation
	  (via audio infoframe, channel-allocation field)

(related docs: HDMI 1.3a spec section 7.4, CEA-861-D section 7.5.3 and 6.6)

This patch attempts to set the CA(channel-allocation) byte in the audio infoframe
according to
	- the number of channels in the current stream
	- the speakers attached to the HDMI sink

A channel_allocations[] line must meet the following two criteria to be
considered as a valid candidate for CA:
	1) its number of allocated channels = substream->runtime->channels
	2) its speakers are a subset of the available ones on the sink side

If there are multiple candidates, the first one is selected.  This simple
policy shall cheat the sink into playing music, but may direct data to the
wrong speakers.

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
---
 sound/pci/hda/patch_intelhdmi.c |  205 ++++++++++++++++++++++++++++++
 1 file changed, 205 insertions(+)

--- sound-2.6.orig/sound/pci/hda/patch_intelhdmi.c
+++ sound-2.6/sound/pci/hda/patch_intelhdmi.c
@@ -89,6 +89,132 @@ struct hdmi_audio_infoframe {
 };
 
 /*
+ * CEA speaker placement:
+ *
+ *        FLH       FCH        FRH
+ *  FLW    FL  FLC   FC   FRC   FR   FRW
+ *
+ *                                  LFE
+ *                     TC
+ *
+ *          RL  RLC   RC   RRC   RR
+ *
+ * The Left/Right Surround channel _notions_ LS/RS in SMPTE 320M corresponds to
+ * CEA RL/RR; The SMPTE channel _assignment_ C/LFE is swapped to CEA LFE/FC.
+ */
+enum cea_speaker_placement {
+	FL  = (1 <<  0),	/* Front Left           */
+	FC  = (1 <<  1),	/* Front Center         */
+	FR  = (1 <<  2),	/* Front Right          */
+	FLC = (1 <<  3),	/* Front Left Center    */
+	FRC = (1 <<  4),	/* Front Right Center   */
+	RL  = (1 <<  5),	/* Rear Left            */
+	RC  = (1 <<  6),	/* Rear Center          */
+	RR  = (1 <<  7),	/* Rear Right           */
+	RLC = (1 <<  8),	/* Rear Left Center     */
+	RRC = (1 <<  9),	/* Rear Right Center    */
+	LFE = (1 << 10),	/* Low Frequency Effect */
+	FLW = (1 << 11),	/* Front Left Wide      */
+	FRW = (1 << 12),	/* Front Right Wide     */
+	FLH = (1 << 13),	/* Front Left High      */
+	FCH = (1 << 14),	/* Front Center High    */
+	FRH = (1 << 15),	/* Front Right High     */
+	TC  = (1 << 16),	/* Top Center           */
+};
+
+/*
+ * ELD SA bits in the CEA Speaker Allocation data block
+ */
+static int eld_speaker_allocation_bits[] = {
+	[0] = FL | FR,
+	[1] = LFE,
+	[2] = FC,
+	[3] = RL | RR,
+	[4] = RC,
+	[5] = FLC | FRC,
+	[6] = RLC | RRC,
+	/* the following are not defined in ELD yet */
+	[7] = FLW | FRW,
+	[8] = FLH | FRH,
+	[9] = TC,
+	[10] = FCH,
+};
+
+struct cea_channel_speaker_allocation {
+	int ca_index;
+	int speakers[8];
+
+	/* derived values, just for convenience */
+	int channels;
+	int spk_mask;
+};
+
+/*
+ * This is an ordered list!
+ *
+ * The preceding ones have better chances to be selected by
+ * hdmi_setup_channel_allocation().
+ */
+static struct cea_channel_speaker_allocation channel_allocations[] = {
+/* 			  channel:   8     7    6    5    4     3    2    1  */
+{ .ca_index = 0x00,  .speakers = {   0,    0,   0,   0,   0,    0,  FR,  FL } },
+				 /* 2.1 */
+{ .ca_index = 0x01,  .speakers = {   0,    0,   0,   0,   0,  LFE,  FR,  FL } },
+				 /* dolby surround */
+{ .ca_index = 0x02,  .speakers = {   0,    0,   0,   0,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x03,  .speakers = {   0,    0,   0,   0,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x04,  .speakers = {   0,    0,   0,  RC,   0,    0,  FR,  FL } },
+{ .ca_index = 0x05,  .speakers = {   0,    0,   0,  RC,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x06,  .speakers = {   0,    0,   0,  RC,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x07,  .speakers = {   0,    0,   0,  RC,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x08,  .speakers = {   0,    0,  RR,  RL,   0,    0,  FR,  FL } },
+{ .ca_index = 0x09,  .speakers = {   0,    0,  RR,  RL,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x0a,  .speakers = {   0,    0,  RR,  RL,  FC,    0,  FR,  FL } },
+				 /* 5.1 */
+{ .ca_index = 0x0b,  .speakers = {   0,    0,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x0c,  .speakers = {   0,   RC,  RR,  RL,   0,    0,  FR,  FL } },
+{ .ca_index = 0x0d,  .speakers = {   0,   RC,  RR,  RL,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x0e,  .speakers = {   0,   RC,  RR,  RL,  FC,    0,  FR,  FL } },
+				 /* 6.1 */
+{ .ca_index = 0x0f,  .speakers = {   0,   RC,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x10,  .speakers = { RRC,  RLC,  RR,  RL,   0,    0,  FR,  FL } },
+{ .ca_index = 0x11,  .speakers = { RRC,  RLC,  RR,  RL,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x12,  .speakers = { RRC,  RLC,  RR,  RL,  FC,    0,  FR,  FL } },
+				 /* 7.1 */
+{ .ca_index = 0x13,  .speakers = { RRC,  RLC,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x14,  .speakers = { FRC,  FLC,   0,   0,   0,    0,  FR,  FL } },
+{ .ca_index = 0x15,  .speakers = { FRC,  FLC,   0,   0,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x16,  .speakers = { FRC,  FLC,   0,   0,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x17,  .speakers = { FRC,  FLC,   0,   0,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x18,  .speakers = { FRC,  FLC,   0,  RC,   0,    0,  FR,  FL } },
+{ .ca_index = 0x19,  .speakers = { FRC,  FLC,   0,  RC,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x1a,  .speakers = { FRC,  FLC,   0,  RC,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x1b,  .speakers = { FRC,  FLC,   0,  RC,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x1c,  .speakers = { FRC,  FLC,  RR,  RL,   0,    0,  FR,  FL } },
+{ .ca_index = 0x1d,  .speakers = { FRC,  FLC,  RR,  RL,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x1e,  .speakers = { FRC,  FLC,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x1f,  .speakers = { FRC,  FLC,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x20,  .speakers = {   0,  FCH,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x21,  .speakers = {   0,  FCH,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x22,  .speakers = {  TC,    0,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x23,  .speakers = {  TC,    0,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x24,  .speakers = { FRH,  FLH,  RR,  RL,   0,    0,  FR,  FL } },
+{ .ca_index = 0x25,  .speakers = { FRH,  FLH,  RR,  RL,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x26,  .speakers = { FRW,  FLW,  RR,  RL,   0,    0,  FR,  FL } },
+{ .ca_index = 0x27,  .speakers = { FRW,  FLW,  RR,  RL,   0,  LFE,  FR,  FL } },
+{ .ca_index = 0x28,  .speakers = {  TC,   RC,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x29,  .speakers = {  TC,   RC,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x2a,  .speakers = { FCH,   RC,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x2b,  .speakers = { FCH,   RC,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x2c,  .speakers = {  TC,  FCH,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x2d,  .speakers = {  TC,  FCH,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x2e,  .speakers = { FRH,  FLH,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x2f,  .speakers = { FRH,  FLH,  RR,  RL,  FC,  LFE,  FR,  FL } },
+{ .ca_index = 0x30,  .speakers = { FRW,  FLW,  RR,  RL,  FC,    0,  FR,  FL } },
+{ .ca_index = 0x31,  .speakers = { FRW,  FLW,  RR,  RL,  FC,  LFE,  FR,  FL } },
+};
+
+/*
  * HDMI routines
  */
 
@@ -260,6 +386,81 @@ static void hdmi_fill_audio_infoframe(st
 		hdmi_write_dip_byte(codec, PIN_NID, params[i]);
 }
 
+/*
+ * Compute derived values in channel_allocations[].
+ */
+static void init_channel_allocations(void)
+{
+	int i, j;
+	struct cea_channel_speaker_allocation *p;
+
+	for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
+		p = channel_allocations + i;
+		p->channels = 0;
+		p->spk_mask = 0;
+		for (j = 0; j < ARRAY_SIZE(p->speakers); j++)
+			if (p->speakers[j]) {
+				p->channels++;
+				p->spk_mask |= p->speakers[j];
+			}
+	}
+}
+
+/*
+ * The transformation takes two steps:
+ *
+ * 	eld->spk_alloc => (eld_speaker_allocation_bits[]) => spk_mask
+ * 	      spk_mask => (channel_allocations[])         => ai->CA
+ *
+ * TODO: it could select the wrong CA from multiple candidates.
+*/
+static int hdmi_setup_channel_allocation(struct hda_codec *codec,
+					 struct hdmi_audio_infoframe *ai)
+{
+	struct intel_hdmi_spec *spec = codec->spec;
+	struct sink_eld *eld = &spec->sink;
+	int i;
+	int spk_mask = 0;
+	int channels = 1 + (ai->CC02_CT47 & 0x7);
+	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+
+	/*
+	 * CA defaults to 0 for basic stereo audio
+	 */
+	if (!eld->eld_ver)
+		return 0;
+	if (!eld->spk_alloc)
+		return 0;
+	if (channels <= 2)
+		return 0;
+
+	/*
+	 * expand ELD's speaker allocation mask
+	 *
+	 * ELD tells the speaker mask in a compact(paired) form,
+	 * expand ELD's notions to match the ones used by audio infoframe.
+	 */
+	for (i = 0; i < ARRAY_SIZE(eld_speaker_allocation_bits); i++) {
+		if (eld->spk_alloc & (1 << i))
+			spk_mask |= eld_speaker_allocation_bits[i];
+	}
+
+	/* search for the first working match in the CA table */
+	for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
+		if (channels == channel_allocations[i].channels &&
+		    (spk_mask & channel_allocations[i].spk_mask) ==
+				channel_allocations[i].spk_mask) {
+			ai->CA = channel_allocations[i].ca_index;
+			return 0;
+		}
+	}
+
+	snd_print_channel_allocation(eld->spk_alloc, buf, sizeof(buf));
+	snd_printd(KERN_INFO "failed to setup channel allocation: %d of %s\n",
+			channels, buf);
+	return -1;
+}
+
 static void hdmi_setup_audio_infoframe(struct hda_codec *codec,
 					struct snd_pcm_substream *substream)
 {
@@ -270,6 +471,8 @@ static void hdmi_setup_audio_infoframe(s
 		.CC02_CT47	= substream->runtime->channels - 1,
 	};
 
+	hdmi_setup_channel_allocation(codec, &ai);
+
 	hdmi_fill_audio_infoframe(codec, &ai);
 }
 
@@ -455,6 +658,8 @@ static int patch_intel_hdmi(struct hda_c
 
 	snd_hda_eld_proc_new(codec, &spec->sink);
 
+	init_channel_allocations();
+
 	return 0;
 }
 

-- 

[PATCH 4/4] hda: HDMI channel mapping cleanups

[Wu Fengguang]

[-- Attachment #1: alsa-speakers2.patch --]
[-- Type: text/plain, Size: 2022 bytes --]

Refactor the channel mapping code for consistent naming
and make it more informed about channel allocations.

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
---
 sound/pci/hda/patch_intelhdmi.c |   29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

--- sound-2.6.orig/sound/pci/hda/patch_intelhdmi.c
+++ sound-2.6/sound/pci/hda/patch_intelhdmi.c
@@ -290,7 +290,7 @@ static void hdmi_set_channel_count(struc
 				chs, hdmi_get_channel_count(codec));
 }
 
-static void hdmi_debug_slot_mapping(struct hda_codec *codec)
+static void hdmi_debug_channel_mapping(struct hda_codec *codec)
 {
 #ifdef CONFIG_SND_DEBUG_VERBOSE
 	int i;
@@ -305,13 +305,6 @@ static void hdmi_debug_slot_mapping(stru
 #endif
 }
 
-static void hdmi_setup_channel_mapping(struct hda_codec *codec)
-{
-	snd_hda_sequence_write(codec, def_chan_map);
-	hdmi_debug_slot_mapping(codec);
-}
-
-
 static void hdmi_parse_eld(struct hda_codec *codec)
 {
 	struct intel_hdmi_spec *spec = codec->spec;
@@ -461,6 +454,22 @@ static int hdmi_setup_channel_allocation
 	return -1;
 }
 
+static void hdmi_setup_channel_mapping(struct hda_codec *codec,
+					struct hdmi_audio_infoframe *ai)
+{
+	if (!ai->CA)
+		return;
+
+	/*
+	 * TODO: adjust channel mapping if necessary
+	 * ALSA sequence is front/surr/clfe/side?
+	 */
+
+	snd_hda_sequence_write(codec, def_chan_map);
+	hdmi_debug_channel_mapping(codec);
+}
+
+
 static void hdmi_setup_audio_infoframe(struct hda_codec *codec,
 					struct snd_pcm_substream *substream)
 {
@@ -472,6 +481,7 @@ static void hdmi_setup_audio_infoframe(s
 	};
 
 	hdmi_setup_channel_allocation(codec, &ai);
+	hdmi_setup_channel_mapping(codec, &ai);
 
 	hdmi_fill_audio_infoframe(codec, &ai);
 }
@@ -569,9 +579,6 @@ static int intel_hdmi_playback_pcm_prepa
 
 	hdmi_set_channel_count(codec, substream->runtime->channels);
 
-	/* wfg: channel mapping not supported by DEVCTG */
-	hdmi_setup_channel_mapping(codec);
-
 	hdmi_setup_audio_infoframe(codec, substream);
 
 	hdmi_enable_output(codec);

-- 

Re: [PATCH 0/4] multi-channel HDMI audio support

[Takashi Iwai]

At Wed, 19 Nov 2008 08:56:14 +0800,
Wu Fengguang wrote:
> 
> Hi Takashi,
> 
> This patchset attempts to support multi-channel HDMI audio.
> 
> It contains two basic operations:
> 
> - setup the CA(channel-allocation) byte in the audio infoframe
> - setup the converter channel to HDMI slot mapping
> 
> Please read patch 3 for more detailed descriptions:
> 
> 	[PATCH 1/4] hda: make standalone hdmi_fill_audio_infoframe()                               
> 	[PATCH 2/4] hda: make global snd_print_channel_allocation()                       
> 	[PATCH 3/4] hda: HDMI channel allocations for audio infoframe                               
> 	[PATCH 4/4] hda: HDMI channel mapping cleanups                                               
> 
> The current implementation only does minimal works that ensure multi-channel
> audio playing out. However the wrong speakers may be selected. We could
> elaborate the framework/policy if it proves to be a problem.

Thanks, applied all patches now.


Takashi

Re: [PATCH 0/4] multi-channel HDMI audio support

[Wu Fengguang]

On Wed, Nov 19, 2008 at 07:39:16AM +0100, Takashi Iwai wrote:
> At Wed, 19 Nov 2008 08:56:14 +0800,
> Wu Fengguang wrote:
> > 
> > Hi Takashi,
> > 
> > This patchset attempts to support multi-channel HDMI audio.
> > 
> > It contains two basic operations:
> > 
> > - setup the CA(channel-allocation) byte in the audio infoframe
> > - setup the converter channel to HDMI slot mapping
> > 
> > Please read patch 3 for more detailed descriptions:
> > 
> > 	[PATCH 1/4] hda: make standalone hdmi_fill_audio_infoframe()                               
> > 	[PATCH 2/4] hda: make global snd_print_channel_allocation()                       
> > 	[PATCH 3/4] hda: HDMI channel allocations for audio infoframe                               
> > 	[PATCH 4/4] hda: HDMI channel mapping cleanups                                               
> > 
> > The current implementation only does minimal works that ensure multi-channel
> > audio playing out. However the wrong speakers may be selected. We could
> > elaborate the framework/policy if it proves to be a problem.
> 
> Thanks, applied all patches now.

Thank you, I'll post more cleanups after a while :-)

Regards,
Fengguang