On Wed, Jan 21, 2026 at 06:54:41PM +0100, 光の夢 wrote: > Known points for bisection: > > 6.17.13-1 ✅ (true suspend) > 6.12.63-1 ❌ (broken suspend) > 6.12.57-1 ✅ (non-broken suspend) > > It seems there aren't any snapshots between 6.12.57-1 and 6.12.63-1, so I > can't find out where this bug started. But I can download the kernel images > to find out when the fix came. > > Bisection log: > > linux-image-6.16.3+deb13-amd64-unsigned 6.16.3-1~bpo13+1 ✅ (true suspend) > linux-image-6.14-amd64-unsigned 6.14.3-1~exp1 ✅ (true suspend) > linux-image-6.13-amd64-unsigned 6.13.7-1~exp1 ✅ (true suspend) > linux-image-6.13-amd64-unsigned 6.13.2-1~exp1 ✅ (true suspend) > linux-image-6.13-rc6-amd64-unsigned 6.13~rc6-1~exp1 ❌❌❌ (fails to boot to > GDM, kernel panic'd once) > linux-image-6.13-rc7-amd64-unsigned 6.13~rc7-1~exp1 ❌❌❌ (fails to boot to GDM) > > So it looks like 6.13.2 is the earliest snapshot available where suspend is > fixed on this laptop. I hope that's helpful. > > I guess I can try to do a git bisect next if that's helpful?
Yes indeed. This would work as follows:
a) clone source code and generate a suitable configuration
git clone --signle-branch -b linux-6.13.y
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
cd linux-stable
git checkout v6.13.2
cp /boot/config-$(uname -r) .config
yes '' | make localmodconfig
make savedefconfig
mv defconfig arch/x86/configs/my_defconfig
b) test v6.13.2 to confirm you have everything you need to compile and
install a kernel and that it's good (as one would expect from your
test of 6.13.2-1~exp1)
make my_defconfig
make -j $(nproc) bindeb-pkg
... install the resulting .deb package and confirm suspend is working
c) Find an older broken one. A conservative choice is 6.12:
git checkout v6.12
make my_defconfig
make -j $(nproc) bindeb-pkg
... install the resulting .deb package 🤞 it boots fine and that
suspend is broken.
If it doesn't boot you have to find another version that boots but
doesn't suspend. v6.13-rc1 or v6.13 might be versions to check.
d) With a)-c) done, the bisection can start:
git bisect start --term-new=fine --term-old=doesntsuspend v6.13.2 v6.12
(Use what ever version you found in c) instead of "v6.12" in the
above command. Also "fine" and "doesntsuspend" are arbitrary terms,
pick whatever you find suitable for you and use is accordingly in the
steps afterwards.)
Whenever you called `git bisect ...` git checks out a version of the
kernel that you are supposed to test. To do so do:
make my_defconfig
make -j $(nproc) bindeb-pkg
... install and test
If the kernel fails to boot or shows another problem that makes you
unable to test if the kernel has the suspend problem run:
git bisect skip
If the kernel suspends and resumes fine (i.e. the problem is fixed)
run:
git bisect fine
and if the suspend problem happens, run
git bisect doesntsuspend
.
e) repeat d) until git reports to have found the first fine revision.
Report back the output of `git bisect log`
The things to pay attention for to are:
- always select the just built kernel for booting. It won't always be
the one the grub picks up as default.
- Typically a system doesn't have enough space (in / and/or /boot) to
be able to install all kernels needed during a bisection. All kernels
that you tested can be uninstalled to make space for the next
package.
- In the end uninstall all kernels you built to not use these
kernels for more than testing.
If you have questions or hit problems, that's probably because my
instructions don't consider all the corner cases you might hit. Don't
hesitate to ask, by mail in reply to this bug or in the #debian-kernel
irc channel.
Thanks for your time and effort,
Uwe
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