[Sorry for breaking threading by pasting the previous email into a new one, but I wasn't subscribed to the list then, so can't just reply...]
Anssi Hannula wrote:
Anssi Hannula kirjoitti keskiviikko, 28. heinkuuta 2010 05:42:09:
Wei Ni kirjoitti tiistai, 27. heinkuuta 2010 10:14:37:
Hi, Takashi MCP7x use old HW design in HDMI, they don't support channel mapping like MCP89. It use nvhdmi_dig_playback_pcm_prepare_8ch() to prepare channel mapping and steam id,format.
Anssi Hannula Please try the following changes in patch_nvhdmi.c static hda_nid_t nvhdmi_con_nids_7x[4] = {
/*front, rear, clfe, rear_surr */
- 0x6, 0x8, 0xa, 0xc,
- 0x6, 0xa, 0x8, 0xc,
};
I actually tried that already, but for some reason changing the order in nvhdmi_con_nids_7x doesn't have any effect.
Actually, disabling the whole for loop that assigns the channels in nvhdmi_dig_playback_pcm_prepare_8ch() has no effect, leading me to believe that the commands are not reaching the hardware or they are being overridden.
Well, I confirmed with AC_VERB_GET_CONV that they are getting through, and they are still the same in nvhdmi_dig_playback_pcm_close_8ch_7x().
Any idea why they are having no effect?
Anssi, As Wei mentioned above, the older MCP7x HW doesn't support this feature. Wei pointed out offline that this was discussed about a year ago. See for example:
http://mailman.alsa-project.org/pipermail/alsa-devel/2009-June/018156.html
In that message, Takashi mentioned something about fixing this in alsa-lib. However, I guess this didn't ever get resolved.
A couple messages later, it appears that Wu Fengguang confirmed that various Intel chipsets also don't support channel mapping, and have a different fixed mapping.
Takashi, is this still something that can/should be solved in alsa-lib?
I also just noticed that the HDMI output is the only detected output, even though this board has analog audio and S/PDIF outputs as well. I'm not sure if this is related or not.
This was not related, updating to latest git fixed it.
-----Original Message----- From: Takashi Iwai [mailto:tiwai at suse.de] Sent: Monday, July 26, 2010 5:35 PM To: Anssi Hannula Cc: alsa-devel at alsa-project.org; Wei Ni Subject: Re: [alsa-devel] Wrong channel order with multichannel HDMI on MCP7A
At Mon, 26 Jul 2010 11:14:17 +0200,
\u79c1 wrote:
At Sun, 25 Jul 2010 19:51:39 +0300,
Anssi Hannula wrote:
Hi all!
I have a motherboard with NVIDIA MCP7A HDMI audio. However, multichannel audio is not mapped properly into the HDMI order.
On 5.1, I get RL in FC, RR in LFE, FC in RL, LFE in RR.
Interestingly, this is not consistent with the ALSA channel order (FL FR RL RR FC LFE) being passed directly to HDMI (FL FR LFE FC RL RR). Instead it looks like there has been a waveformatex (FL FR FC LFE RL RR; windows?) => HDMI conversion instead of ALSA => HDMI.
Same happens for 7.1.
Is it possible to set the hardware to do an ALSA => HDMI conversion instead? If not, we should manually compensate for this somewhere, right?
Does the patch below change anything?
Ah crap, it should be irrelevant. Wei, don't MCP 7x chips support the channel mapping as MCP 89?
thanks,
Takashi
Somewhat relatedly, trying to output 4 channels results in silence only.
Although 5.1/7.1 work?
Trying to output 3 or 5 channels triggers a timeout with I/O error, with the following in the kernel log: "ALSA pcm_lib.c:1757: playback write error (DMA or IRQ trouble?)"
HD-audio doesn't support the odd number of channels in general, so they should be played as 4 or 6 channels. But, it looks like something wrong in the setup...
thanks,
Takashi
diff --git a/sound/pci/hda/patch_nvhdmi.c b/sound/pci/hda/patch_nvhdmi.c index 3c10c0b..7355c60 100644 --- a/sound/pci/hda/patch_nvhdmi.c +++ b/sound/pci/hda/patch_nvhdmi.c @@ -511,6 +511,8 @@ static int patch_nvhdmi_8ch_7x(struct hda_codec *codec)
codec->patch_ops = nvhdmi_patch_ops_8ch_7x;
init_channel_allocations();
return 0;
}