[alsa-devel] Missing surround channels with Nvidia HDMI & snd-hda-intel driver

[Takashi Iwai]

On Thu, 16 Nov 2017 06:53:37 +0100,
VDR User wrote:
> 
> Ok, after doing a git bisect on the kernel tree, I wound up with:
> 
> 41eb94fd26f6c150b0460e01ecc84d643355f9b6 is the first bad commit
> commit 41eb94fd26f6c150b0460e01ecc84d643355f9b6
> Author: Vinod Koul <vinod.koul at intel.com>
> Date:   Fri Mar 4 20:25:30 2016 +0530
> 
>     ALSA: compress: fix some typos
> 
> So, something must have went wrong because that commit is just
> spelling and grammar fixes in comments.

Yeah, that's very unlikely.

> How can I do a git bisect for just sound/ instead of the whole kernel?
> I assume I'd have to clone the kernel, delete sound/, then clone the
> alsa dev git sound/ in its place? It should be easier to git bisect in
> alsa, then simply recompile modules, install, load, test, and repeat
> until I find the offending commit right?

What you can try is to bisect like
   git bisect start -- sound/hda sound/pci/hda
   git bisect good v4.5
   git bisect bad v4.6-rc1

This will concentrate only on commits in sound/hda/* and
sound/pci/hda/*.  You have to be careful about the kernel version to
be built eventually jumping back and forth, and remember which one is
installed and rebooted/retested.  I usually put a different suffix
string to CONFIG_LOCALVERSION at each build or set
CONFIG_LOCALVERSION_AUTO to put the git commit id.


Takashi

> On Wed, Nov 15, 2017 at 8:34 AM, VDR User <user.vdr at gmail.com> wrote:
> >>> It just tried kernel 4.6-rc1 and the problem is present there as well.
> >>> Is there a list of patches between stable kernel 4.5.7 and 4.6-rc1
> >>> somewhere? I can try to revert each of them one at a time if so.
> >>> Unless someone has any better idea to narrow this down to the
> >>> offending commit?
> >>
> >> There were a significant amount of changes between 4.5 and 4.6
> >> regarding HD-audio HDMI/DP due to DP-MST support and the movement of
> >> chmap stuff into sound/hda.
> >>
> >> Both can be a culprit...
> >>
> >> For checking the former, could you try the following?
> >> - Checkout 4.5.7 git branch
> >> - merge (not cherry-pick) the commit 022f344b41a5
> >>   % git merge 022f344b41a5
> >>
> >>   This will bring DP-MST changes on top of 4.5.7.
> >>
> >> Then build this and check whether it shows the problem.  If yes, you
> >> can easily bisect between 4.5.7 and here.  If it doesn't show a
> >> problem, the problem is in the rest changes in 4.6-rc1.
> >
> > Hi Takashi,
> >
> > I did:
> > git clone https://github.com/torvalds/linux.git
> > cd linux
> > git checkout 022f344b41a5
> >
> > After compiling, audio is working correctly with that commit:
> > ~$ speaker-test -c 6 -t wav
> >
> > speaker-test 1.1.3
> >
> > Playback device is default
> > Stream parameters are 48000Hz, S16_LE, 6 channels
> > WAV file(s)
> > Rate set to 48000Hz (requested 48000Hz)
> > Buffer size range from 64 to 5440
> > Period size range from 32 to 2720
> > Using max buffer size 5440
> > Periods = 4
> > was set period_size = 1088
> > was set buffer_size = 5440
> >  0 - Front Left
> >  4 - Front Center
> >  1 - Front Right
> >  3 - Rear Right
> >  2 - Rear Left
> >  5 - LFE
> > Time per period = 8.526391
> >
> > Do you happen to known which commit I can try next that *should* have
> > the problem so I can git bisect from there?
> >
> > Thanks!
>