I am working on an embedded system built around Atmel ARM926EJ-S based on rather old ARM core ARMv5TEJ. I have a Debian 8 system that used to work for that hardware until I had to update the kernel from 3.11.6 to 4.1.18. The update was needed in order to add support for certain USB hardware.The update gave me what I wanted with one exception: reboot is not working anymore. More precisely put, when I write command reboot into console, the system shuts itself down, but in the end, instead of actually rebooting the CPU, it just halts, requiring use of the power switch to get the system up again.What could cause this? Are there any typical issues that I could check?Here are the last lines of the debug console:systemd-shutdown[1]: Sending SIGTERM to remaining processes...systemd-journald[721]: Received SIGTERM from PID 1 (systemd-shutdow).systemd-shutdown[1]: Sending SIGKILL to remaining processes...systemd-shutdown[1]: Unmounting file systems.systemd-shutdown[1]: Unmounting /sys/kernel/debug.EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)systemd-shutdown[1]: All filesystems unmounted.systemd-shutdown[1]: Deactivating swaps.systemd-shutdown[1]: All swaps deactivated.systemd-shutdown[1]: Detaching loop devices.systemd-shutdown[1]: All loop devices detached.systemd-shutdown[1]: Detaching DM devices.systemd-shutdown[1]: All DM devices detached.systemd-shutdown[1]: Rebooting.reboot: Restarting systemReboot failed -- System halted
How to fix reboot broken by kernel update
debian;linux kernel;embedded;reboot
I tried kernel version 4.11.0 which is the latest stable version at the moment, as suggested in the comments to the question. There were some new options regarding reboot and it works now.I didn't investigate the details further so I can't tell whether something had been broken and then got fixed again or if version 4.1.18 could have been fixed with proper configuration.