Dear Maintainer,
--- Details ---
A regression has been introduced in kernel version 6.12.113 affecting the AMD Renoir xHCI USB controllers [1022:1639]. USB hotplug detection completely breaks after boot, though all devices connected at boot enumerate successfully.

--- Symptom ---
- All peripheral devices enumerate correctly during boot.
- After boot, zero insertion interrupts are reported by xHCI. No dmesg lines appear and no errors are logged when plugging/unplugging devices on all ports except one (port 3-2 on controller 04:00.4).
- Reproduced using both a Wavlink USB-C dock (Fresco Logic FL1100 hub) and direct connections.

--- Regression Testing ---
- Works correctly on: Linux 6.12.107 (and 6.12.101)
- Broken on: Linux 6.12.113

--- Troubleshooting / Ruled Out ---
- `usbcore.autosuspend=-1` added to kernel command line has no effect.
- Runtime PM is not the cause (`power/runtime_status = active`).
- No xHCI-specific errors are present in `dmesg`.

--- Hardware Information ---
- Machine: Acemagic AMO6
- DMI: HC Technology HCAR5000-MI, BIOS 0.33 (09/25/2025)
- Processor: AMD Ryzen 7 7730U
- USB Controllers: xHCI 0000:04:00.3 and 0000:04:00.4 [1022:1639]

Hi,

As you are experiencing the regression from 6.12.107-1 can you please
bisect the changes upstream and report back what is the causing
change.

    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 v6.12.107
    cp /boot/config-$(uname -r) .config
    yes '' | make localmodconfig
    make savedefconfig
    mv defconfig arch/x86/configs/my_defconfig

    # test 6.12.107 to ensure this is "good"
    make my_defconfig
    make -j $(nproc) bindeb-pkg
    ... install the resulting .deb package and confirm problem does not exist

    # test 6.12.113 to ensure this is "bad"
    git checkout v6.12.113
    make my_defconfig
    make -j $(nproc) bindeb-pkg
    ... install the resulting .deb package and confirm problem exists

With that confirmed, the bisection can start:

    git bisect start --first-parent
    git bisect good v6.12.107
    git bisect bad v6.12.113

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, verify if problem exists

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.

Iterate until git announces to have identified the first bad commit.

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

Thank you Salvatore,

I started the process and wrongly marked a commit as good when it is bad. I realize that on 6.12.113, the issue no longer occurs when I disconnect power from my AM06 mini PC. Issue however happens during reboot or warm boot.

I need to start over with that in mind but am traveling this week.

Thank you for sharing the steps, I will resume and revert back next week.

Kind regards,
Youl

Le 24 octobre 2026 17:06:45 GMT+02:00, Salvatore Bonaccorso <carnil@debian.org> a écrit :