Re: [Intel-gfx] Problems with HDMI audio on Intel DG45FC motherboard

["David Härdeman" <david@hardeman.nu>]

On Tue, Oct 20, 2009 at 03:43:53PM -0700, Shane W wrote:
> On Tue, Oct 20, 2009 at 09:26:00AM +0800, Wu Fengguang wrote:
> > HDMI codec/sink seem to take some time to response to the output
> > enable and new infoframe, so there are some delay. I've moved the HDMI
> > output enable command to module load time, this helps. The infoframe
> > is in theory created in run time based on the format of _each_ new
> > audio stream, so infoframe transmission has to be started/stopped
> > for each track..
> 
> I know this has come up before but can't we not start/stop
> the infoframe if the sample format on the new track is the
> same as the old. I mean playing an album, you're gonna get
> 44100, 2ch s16le 95% of the time so that would atleast
> cause the problem to appear much less.

Tried it, still had the second-track-produces-silence bug on my receiver 
so I couldn't test it properly.

I however did manage to create a different patch which fixed my receiver 
bug (yay!)...by sending "refer-to-stream-header" audio infoframes from 
pcm close to pcm open...something like this quick hack:


--- linux-2.6.32-rc5/sound/pci/hda/patch_intelhdmi.c	2009-10-16 02:41:50.000000000 +0200
+++ ../linux-2.6.32-rc5/sound/pci/hda/patch_intelhdmi.c	2009-10-26 23:39:54.000000000 +0100
@@ -552,8 +552,16 @@
 					 struct snd_pcm_substream *substream)
 {
 	struct intel_hdmi_spec *spec = codec->spec;
+	struct hdmi_audio_infoframe ai = {
+		.type		= 0x84,
+		.ver		= 0x01,
+		.len		= 0x0a,
+		.CC02_CT47	= 0x00,
+	};
 
 	hdmi_stop_infoframe_trans(codec);
+	hdmi_fill_audio_infoframe(codec, &ai);
+	hdmi_start_infoframe_trans(codec);
 
 	return snd_hda_multi_out_dig_close(codec, &spec->multiout);
 }
@@ -571,6 +579,7 @@
 
 	hdmi_set_channel_count(codec, substream->runtime->channels);
 
+	hdmi_stop_infoframe_trans(codec);
 	hdmi_setup_audio_infoframe(codec, substream);
 
 	return 0;


Not sure how/if something like that could be turned into an acceptable 
patch though...

-- 
David Härdeman

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