Dear Maintainer,

After upgrading to kernel 7.1.8, the system freezes when Alt+Tabbing
out of fullscreen games (tested with Fallout Shelter via Steam/Proton).

dmesg shows:
amdgpu 0000:0a:00.0: [drm] *ERROR* [CRTC:422:crtc-0] flip_done timed out
amdgpu 0000:0a:00.0: [drm] *ERROR* flip_done timed out
amdgpu 0000:0a:00.0: [drm] *ERROR* [CRTC:422:crtc-0] commit wait timed out

Hardware: AMD Radeon RX 6600 (Navi 23), Ryzen 7 5700X,
Gigabyte B550 AORUS ELITE V2 (BIOS FId, 2026-08-18), 128 GB RAM.

Kernel 7.1.3 works fine with same hardware and same games.
The problem is a regression introduced in 7.1.8.

Workaround: revert to kernel 7.1.3 and pin it via apt-mark hold.

I already tried amdgpu.dcdebugmask=0x410 and it did not help.

Note: currently running 7.1.3 (as shown in System Information below),
because 7.1.8 is unusable due to this bug.

ii  firmware-amd-graphics                        20260810-1~bpo13+1                          all          Binary firmware for AMD/ATI graphics and NPU chips
ii  libegl-mesa0:amd64                           25.0.7-2+deb13u1                            amd64        free implementation of the EGL API -- Mesa vendor library
ii  libegl-mesa0:i386                            25.0.7-2+deb13u1                            i386         free implementation of the EGL API -- Mesa vendor library
ii  libegl1-mesa:amd64                           22.3.6-1+deb12u1                            amd64        transitional dummy package
ii  libegl1-mesa-dev:amd64                       25.0.7-2+deb13u1                            amd64        free implementation of the EGL API -- development files
ii  libgl1-mesa-dri:amd64                        25.0.7-2+deb13u1                            amd64        free implementation of the OpenGL API -- DRI modules
ii  libgl1-mesa-dri:i386                         25.0.7-2+deb13u1                            i386         free implementation of the OpenGL API -- DRI modules
ii  libglu1-mesa:amd64                           9.0.2-1.1+b3                                amd64        Mesa OpenGL utility library (GLU)
ii  libglx-mesa0:amd64                           25.0.7-2+deb13u1                            amd64        free implementation of the OpenGL API -- GLX vendor library
ii  libglx-mesa0:i386                            25.0.7-2+deb13u1                            i386         free implementation of the OpenGL API -- GLX vendor library
ii  mesa-common-dev:amd64                        25.0.7-2+deb13u1                            amd64        Developer documentation for Mesa
ii  mesa-libgallium:amd64                        25.0.7-2+deb13u1                            amd64        shared infrastructure for Mesa drivers
ii  mesa-libgallium:i386                         25.0.7-2+deb13u1                            i386         shared infrastructure for Mesa drivers
ii  mesa-utils                                   9.0.0-2+b2                                  amd64        Miscellaneous Mesa utilities -- symlinks
ii  mesa-utils-bin:amd64                         9.0.0-2+b2                                  amd64        Miscellaneous Mesa utilities -- native applications
ii  mesa-va-drivers:amd64                        25.0.7-2+deb13u1                            amd64        Mesa VA-API video acceleration drivers
ii  mesa-va-drivers:i386                         25.0.7-2+deb13u1                            i386         Mesa VA-API video acceleration drivers
ii  mesa-vdpau-drivers:amd64                     25.0.7-2+deb13u1                            amd64        Mesa VDPAU video acceleration drivers
ii  mesa-vulkan-drivers:amd64                    25.0.7-2+deb13u1                            amd64        Mesa Vulkan graphics drivers
ii  mesa-vulkan-drivers:i386                     25.0.7-2+deb13u1                            i386         Mesa Vulkan graphics drivers

Hi,

Can you please check if this is still reproducible with 7.2.9-1? Can
you additionally in case reproducible with 7.2.9-1 test without the
amdgpu.gpu_recovery=1 kernel parameter, and report back?

Regards,
Salvatore