Is it possible that the issue might be related to the hardware watchdog timer? I note the following lines in the dmesg output:
[ 2.214004] bcm2835-wdt bcm2835-wdt: Broadcom BCM2835 watchdog timer [ 2.288820] watchdog: Delayed init of the lockup detector failed: -19 [ 2.295372] watchdog: Hard watchdog permanently disabled Is this expected output for a CM4? I've tried researching how to enable it but am a little out of my depth. cat /boot/config-$(uname -r) | grep BCM2835_WDT CONFIG_BCM2835_WDT=y This suggests the BCM2835 support is compiled into the kernel. Are there any other configuration items I can modify to properly enable the hard watchdog? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2099935 Title: PCI initialization failure following kernel panic reboot on Raspberry Pi CM4 Status in linux package in Ubuntu: Invalid Status in linux-raspi package in Ubuntu: Confirmed Bug description: Ubuntu Server 24.10 Linux ubuntu 6.11.0-1004-raspi #4-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 27 22:25:34 UTC 2024 aarch64 aarch64 aarch64 GNU/Linux We're seeing that following a kernel panic and reboot, the PCI fails to initialize correctly and associated devices (such as Wi-Fi card) are not available. Issue Description: • On the first boot, everything works correctly. • However, after a Kernel Panic, the device reboots, but PCIe does not reset or re-initialize properly. • When this happens: o The Wi-Fi card is not recognized. o The lspci command shows no PCI devices. o The dmesg log includes the message: [ 0.591441] brcm-pcie fd500000.pcie: link down • A soft reboot does not fix the issue. • The only way to recover is to completely remove and reconnect power (hard reboot). We have tried modifying /boot/firmware/config.txt and /boot/firmware/cmdline.txt, which has reduced but not fully resolved the issue. How to Reproduce The Problem: 1. Power up the hardware 2. Run ‘lspci’ – observe the result includes the PCI Bridge and Wi-Fi card 3. Trigger a kernel panic with the command ‘echo c | sudo tee /proc/sysrq-trigger’, causing a reboot 4. Run ‘lspci’ – observer the output is now empty The same issue does not occur on Raspberry Pi OS - it seems to be specific to Ubuntu. Any assistance/guidance on how to troubleshoot this would be much appreciated! To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2099935/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
