Bug#1110046: linux-image-6.12.38+deb13-amd64: Audio fails to play

[Salvatore Bonaccorso <carnil@debian.org>]

Hi,

On Sat, Aug 02, 2025 at 10:39:44AM +0200, skrap@anakin.se wrote:
> Noticed, after more testing, that if I put computer to suspend and woke
> it, the sound have issues after woke up on 6.16

Thanks for testing.

Comparing the diff was hot helpful (to me unfortunately, did not spot
something obvious). So let's go the bisect route, I will replicate the
excellent small howto from Uwe Kleine-Koenig here.

The whole will involve to compile multiple kernels. First we need to
prepare a config for your system and to prepare the respective
upstream versions, in your case we want to bisect the stable versions
in one specific branch, so we can shortcut, and we know we want to
bisect changes between 6.12.35 and 6.12.38 in your case.

    git clone --single-branch -b linux-6.12.y https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
    cd linux-stable
    git checkout v6.12.35
    cp /boot/config-$(uname -r) .config
    yes '' | make localmodconfig
    make savedefconfig
    mv defconfig arch/x86/configs/my_defconfig

As a fist step now compile a local 6.12.35 to ensure it is "good".

    # test 6.12.35 to ensure this is "good"
    make my_defconfig
    make -j $(nproc) bindeb-pkg
    ... install the resulting .deb package and confirm the problem is not present.

And now the same for the version you suspect is broken, is "bad" for
git bisect speach.

    # test 6.12.38 to ensure this is "bad"
    git checkout v6.12.38
    make my_defconfig
    make -j $(nproc) bindeb-pkg
    ... install the resulting .deb package and confirm the problem with audio exists.

So we have now a range of from good to bad kernel and we can start the
bisect:

    git bisect start v6.12.38 v6.12.35

In each bisection step git checks out a state between the oldest
known-bad and the newest known-good commit. In each step test using:
 
    make my_defconfig
    make -j $(nproc) bindeb-pkg
    ... install, try to boot and verify the state of the problem

and if the problem is hit run:
 
    git bisect bad
 
and if the problem doesn't trigger run:
 
    git bisect good

. Please pay attention to always select the just built kernel for
booting, it won't always be the default kernel picked up by grub.

Then provide the output of
 
    git bisect log
 
In the course of the bisection you might have to uninstall previous
kernels again to not exhaust the disk space in /boot. Also in the end
uninstall all self-built kernels again. 

Regards,
Salvatore