Control: tags -1 + moreinfo Hi,
On Tue, Jul 07, 2026 at 07:37:24AM +0200, Ponali wrote: > Package: src:linux > Version: 6.12.94-1 > Severity: normal > Tags: upstream, regression > X-Debbugs-Cc: [email protected] > > Last known working kernel: 6.12.90-1 > First known broken kernel: 6.12.94-1 > > > Dear Maintainer, > > I upgraded all my packages through apt, which also upgraded the linux image > from 6.12.90 to 6.12.94. > > I expected the ScreenPad display to continue to be detected and exposed as a > DRM output, like on 6.12.90. The ScreenPad being the trackpad with a screen, > which came with my computer (ASUS VivoBook X532FA_S532FA). > > After upgrading and rebooting, the new kernel caused a regression where the > display of the ScreenPad fails to get recognized by the kernel. The touchpad > functionality still works. Usually, the ScreenPad would appear as "HDMI-A-1". > The DRM connector for it still exists (/sys/class/drm/card0-HDMI-A-1), but > "status" reports "disabled" > > I could not get the ScreenPad display to be recognized again on the new > kernel, > so I configured GRUB to automatically boot to the 6.12.90 kernel through the > "Advanced Options". The ScreenPad is recognized on older kernel versions, so I > am still able to use it (until a new LPE comes around). > > To replicate: > 1. Boot with 6.12.90. The ScreenPad display is detected as HDMI-A-1. > 2. Boot with 6.12.94 with the exact same hardware. > 3. The ScreenPad display is no longer usable. > > > My main display is eDP-1 (1920x1080), though it isn't essential. My GPU is an > integrated Intel iGPU, and the driver used for both screens is i915. I have > booted to the new kernel for reportbug to get all the information > automatically, but i will continue to use the old one until the appropriate > time. As a first step, please verify if the problem persists in 6.12.95-1 as released. If yes then proceed with the next paragraph. Can you please bisect the changes between 6.12.90 and 6.12.94 upstream please? Doing so will require to compile and testing a couple of kernels: 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 v6.12.90 cp /boot/config-$(uname -r) .config yes '' | make localmodconfig make savedefconfig mv defconfig arch/x86/configs/my_defconfig # test 6.12.90 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 6.12.94 to ensure this is "bad" git checkout v6.12.94 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 git bisect good v6.12.90 git bisect bad v6.12.94 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. Thanks already. Regards, Salvatore
