Surround sound broken in HDMI audio in kernel 2.6.36 to present!

primerib · 02-06-11, 11:28 AM

Hi. Some changes happened to the alsa drivers which broken surround sound with HDMI audio. It seems to have started with kernel 2.6.36 and continues thru to the current 2.6.37 kernel. Using alsa git drivers doesn't fix it either.

Do anyone have a patch to fix this?

Thanks.

gradinaruvasile · 02-06-11, 12:43 PM

I dont know about HDMI, but ALSA is partially broken in the 2.6.37 kernel (Debian 32-bit + nvidia 8200/MCP78).
I cant use the front mic (it has an entry in the mixer table), with the stock Squeeze 2.6.32 kernel it works just fine.

primerib · 02-06-11, 01:19 PM

There's no doubt HDMI audio is broken for surround sound channels cuz even when ELD reports them there, speaker-test still doesn't work on them. L/R stereo still work though. Reverting to kernel 2.6.35.* works but this needs to be fixed, especially in "stable" kernels.

Cyclone131 · 02-07-11, 12:49 AM

Surround works with alsa-driver 1.0.23 but not 1.0.24. With 1.0.24, I get only left and right.

If someone could suggest instructions for bisecting the alsa-driver and alsa-kmirror git trees, it might be feasible to track down the culprit. I tried bisecting one but couldn't find a commit in the other that would let it build.

dura91 · 02-07-11, 08:25 AM

Quote:

Originally Posted by Cyclone131

Surround works with alsa-driver 1.0.23 but not 1.0.24. With 1.0.24, I get only left and right.

If someone could suggest instructions for bisecting the alsa-driver and alsa-kmirror git trees, it might be feasible to track down the culprit. I tried bisecting one but couldn't find a commit in the other that would let it build.

I've already made a bisect on this problem. I will post the id of the bad commit and the corresponding revert patch when I come back to home. Multi-channel LPCM is working again with the wrong commit reverted.

mooninite · 02-07-11, 10:31 AM

Quote:

Originally Posted by dura91

I've already made a bisect on this problem. I will post the id of the bad commit and the corresponding revert patch when I come back to home. Multi-channel LPCM is working again with the wrong commit reverted.

You should file a bug at https://bugzilla.kernel.org/ with your bisect findings so they can fix it.

primerib · 02-07-11, 11:13 AM

Quote:

Originally Posted by dura91

I've already made a bisect on this problem. I will post the id of the bad commit and the corresponding revert patch when I come back to home. Multi-channel LPCM is working again with the wrong commit reverted.

That is great news! There's some posts on the alsa-devel mailing list about it but they haven't seemed interested in fixing it. Thanks for taking the time to look into it and resolve the problem!

dura91 · 02-07-11, 03:47 PM

Quote:

Originally Posted by primerib

That is great news! There's some posts on the alsa-devel mailing list about it but they haven't seemed interested in fixing it. Thanks for taking the time to look into it and resolve the problem!

There's a lot of threads on this list, I was not able to locate the one talking about the problem.
The bad commit is:
http://git.kernel.org/?p=linux/kerne...ee0774aaaef5c0
The 2.6.36 kernel is not affected, so this might not be the problem that primerib initially want to report.
Like mooninite suggested, I will fill a bug report on https://bugzilla.kernel.org/

primerib · 02-07-11, 07:05 PM

Quote:

Originally Posted by dura91

There's a lot of threads on this list, I was not able to locate the one talking about the problem.
The bad commit is:
http://git.kernel.org/?p=linux/kerne...ee0774aaaef5c0
The 2.6.36 kernel is not affected, so this might not be the problem that primerib initially want to report.
Like mooninite suggested, I will fill a bug report on https://bugzilla.kernel.org/

Are you sure 2.6.36 isn't affected? I reversed the commit you posted and sure enough it fixed the missing surround sound channels! Looks like we killed 2 birds with one stone here. Thanks for posting the info!

dura91 · 02-08-11, 07:48 AM

Quote:

Originally Posted by primerib

Are you sure 2.6.36 isn't affected? I reversed the commit you posted and sure enough it fixed the missing surround sound channels! Looks like we killed 2 birds with one stone here. Thanks for posting the info!

There was no such problem with 2.6.36 for me.
Bugzilla entry is https://bugzilla.kernel.org/show_bug.cgi?id=28592

02-06-11, 11:28 AM	#1
primerib Registered User Join Date: Dec 2008 Posts: 128	Surround sound broken in HDMI audio in kernel 2.6.36 to present! Hi. Some changes happened to the alsa drivers which broken surround sound with HDMI audio. It seems to have started with kernel 2.6.36 and continues thru to the current 2.6.37 kernel. Using alsa git drivers doesn't fix it either. Do anyone have a patch to fix this? Thanks.

02-06-11, 12:43 PM	#2
gradinaruvasile Registered User Join Date: May 2008 Posts: 199	Re: Surround sound broken in HDMI audio in kernel 2.6.36 to present! I dont know about HDMI, but ALSA is partially broken in the 2.6.37 kernel (Debian 32-bit + nvidia 8200/MCP78). I cant use the front mic (it has an entry in the mixer table), with the stock Squeeze 2.6.32 kernel it works just fine.

02-06-11, 01:19 PM	#3
primerib Registered User Join Date: Dec 2008 Posts: 128	Re: Surround sound broken in HDMI audio in kernel 2.6.36 to present! There's no doubt HDMI audio is broken for surround sound channels cuz even when ELD reports them there, speaker-test still doesn't work on them. L/R stereo still work though. Reverting to kernel 2.6.35.* works but this needs to be fixed, especially in "stable" kernels.

02-07-11, 12:49 AM	#4
Cyclone131 Registered User Join Date: Feb 2011 Posts: 1	Re: Surround sound broken in HDMI audio in kernel 2.6.36 to present! Surround works with alsa-driver 1.0.23 but not 1.0.24. With 1.0.24, I get only left and right. If someone could suggest instructions for bisecting the alsa-driver and alsa-kmirror git trees, it might be feasible to track down the culprit. I tried bisecting one but couldn't find a commit in the other that would let it build.