Video problems after last upgrades

Support Graphics & Display
1

Hi everybody
I have Lenovo ThinkPad T420 (yeah, an anchient one!)

$ inxi -C
CPU: dual core Intel Core i5-2520M (-MT MCP-) speed/min/max: 1991/800/3200 MHz
Kernel: 7.0.10-1-MANJARO x86_64 Up: 20m Mem: 6.68/15.5 GiB (43.1%)
Storage: 1.82 TiB (67.3% used) Procs: 268 Shell: Bash inxi: 3.3.40

$ inxi -G
Graphics:
  Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics
    driver: i915 v: kernel
  Device-2: Chicony integrated camera driver: uvcvideo type: USB
  Display: unspecified server: X.Org v: 21.1.22 with: Xwayland v: 24.1.11
    driver: X: loaded: modesetting dri: crocus gpu: i915 resolution:
    1: 1920x1080~60Hz 2: 1600x900~60Hz
  API: EGL v: 1.5 drivers: crocus,swrast
    platforms: gbm,x11,surfaceless,device
  API: OpenGL v: 4.5 compat-v: 3.3 vendor: intel mesa v: 26.0.6-arch1.1
    renderer: Mesa Intel HD Graphics 3000 (SNB GT2)
  API: Vulkan Message: No Vulkan data available.
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: gputop, intel_gpu_top, lsgpu
    wl: wayland-info x11: xdpyinfo, xprop, xrandr

Using KDE/Plasma, all last upgrades.
Suddenly when decided to watch a movie, got such picture:

IMG_20260607_151222
IMG_20260607_1512221081Ă—811 194 KB

When i tried to make screenshot, it went even worse:

IMG_20260607_151203
IMG_20260607_1512031081Ă—811 250 KB

Of course first thought was “Good bye videocard”, but then i’ve asked Claude code and this is what I got:

T420 Mesa video corruption — resolved

** Root cause: Mesa 26.1.1 (installed 2026-05-28) introduced a regression in the crocus driver for your gen6 GPU (HD Graphics 3000 / Sandy**
** Bridge). It corrupted GPU-rendered surfaces — vertical bars / checkerboarding in mpv (vo=gpu), KWin compositing, and Spectacle — on both**
** LVDS-1 and the HDMI ViewSonic.**

** How it was diagnosed:**
** - LIBGL_ALWAYS_SOFTWARE=1 (llvmpipe) rendered clean → not the hardware/panel/cable.**
** - hwdec=no still corrupted → not VA-API decode.**
** - Conclusion: the fault was specifically the crocus GL path, not silicon.**

** Fix applied:**
** - Downgraded mesa + lib32-mesa to 1:26.0.6-1 (last known-good, ran fine May 3–28) from the pacman cache.**
** - Pinned them via IgnorePkg = mesa lib32-mesa in /etc/pacman.conf (line 29).**
** - Backup left at /etc/pacman.conf.bak.20260607-153227.**

** Bottom line: It’s a software regression, not failing hardware — the T420 is fine. The pin holds you on 26.0.6. Only remove the IgnorePkg**
** line to test a newer Mesa after the crocus/gen6 regression is fixed upstream, and re-test video + desktop before trusting it.**

After making this correction and reboot now everything is ok. So it seems to be some problem with Mesa 26.1.1.

2

It appears to be a problem with mesa on older (1st and 2nd generation) Intel Core processors. :backhand_index_pointing_down:

A newer version of mesa is already in the Unstable branch and will probably soon be in the Testing branch, so it’s on the way down to Manjaro Stable.

1 Like
3

You probably missed the announcement where i wrote to wait with the update (or you were one of the first, before the problem was known). Anyway, do not add it to ignore list, since the patched version is already in unstable branch and it is a matter of time to trickle down. And you want it.

1 Like