Does anyone face the same issue? This Morning after a reboot of two machines an automatic kerne update form 6.12.47 to 6.12.62 killed all my HDMI monitor outputs. Those are the details:After an automatic upgrade to kernel 6.12.62+rpt on Raspberry Pi OS Trixie (arm64), HDMI output stops working completely on Raspberry Pi 4 and Raspberry Pi 5.
The system boots, VNC works, SSH works, but no HDMI signal is detected on any monitor or cable.
This regression is 100% reproducible and affects all current official Raspberry Pi OS images, because they all ship with or upgrade to kernel 6.12.x.
Affected hardware
• Raspberry Pi 4 Model B (4 GB)
• Raspberry Pi 5 (8 GB)
Both devices show identical behavior.
Affected OS versions
• Raspberry Pi OS Trixie (64‑bit), fresh install from Raspberry Pi Imager
• All images released after November 2025
• All “Legacy” images currently offered (they also contain kernel 6.12.x)
Kernel versions
Working:
• 6.6.x (Bookworm kernel)
• 6.1.x (older Bookworm kernel)
Broken:
• 6.12.47+rpt
• 6.12.62+rpt ← confirmed regression
Exact time of the automatic kernel upgrade
From /var/log/dpkg.log:
2026-02-13 13:47:53 install linux-image-6.12.62+rpt-rpi-2712:arm64 <none> 1:6.12.62-1+rpt1
2026-02-13 13:47:55 install linux-image-6.12.62+rpt-rpi-v8:arm64 <none> 1:6.12.62-1+rpt1
The upgrade was automatic, not user‑initiated.
HDMI stopped working after the next reboot, not immediately after installation.
Observed behavior
• System boots normally
• Green LED activity normal
• SSH works
• VNC works
• System is fully reachable
• HDMI output is completely dead
○ no signal
○ no flicker
○ no rainbow screen
○ no tty
○ no desktop
Tested with:
• multiple monitors
• multiple HDMI cables
• both micro‑HDMI ports (Pi 4)
• both HDMI ports (Pi 5)
Same result everywhere.
Expected behavior
HDMI output should work as with kernel 6.6.x and earlier.
Steps to reproduce
1. Flash any current Raspberry Pi OS Trixie image (64‑bit)
2. Boot Raspberry Pi 4 or 5
3. Let the system install updates automatically
4. Reboot
5. HDMI output is gone
Alternatively:
• Install kernel 6.12.62+rpt-rpi-v8 or 6.12.62+rpt-rpi-2712 manually
• Reboot
• HDMI output disappears
Impact
• All new Raspberry Pi 4/5 installations using official images have no HDMI output
• All existing systems with automatic updates will lose HDMI after reboot
• Devices appear “dead” to inexperienced users
• This affects:
○ education
○ industry
○ makers
○ retail devices
○ second‑hand devices (buyers think they are defective)
This is a critical regression.
Additional notes
• VNC still works → GPU stack partially functional
• No errors in dmesg related to HDMI
• Issue appears to be in the DRM/KMS pipeline for Pi 4/5 in kernel 6.12.x
• Rolling back to kernel 6.6.x restores HDMI immediately
• No hardware faults involved
Request
Please investigate the HDMI regression in kernel 6.12.x for Raspberry Pi 4 and 5.
A temporary workaround would be:
• re‑publishing a Bookworm image with kernel 6.6.x
• or pinning kernel 6.6.x until the regression is fixed
• or providing an official downgrade path
This issue currently affects all new installations and all updated systems.
Statistics: Posted by UweG — Mon Feb 16, 2026 7:11 pm — Replies 2 — Views 41