Code:
rk_gmac-dwmac fe300000.ethernet eth0: stmmac_hw_setup: DMA engine initialization failed
I've been using the debian unstable 5.10 kernel for months without this problem, but it finally appeared today. I'm currently using linux-image-arm64/unstable 5.10.12-1 . Except for small handful of applications, the system is otherwise running debian buster.
It's curious that dropbear-initramfs configures eth0 just fine (with my workaround for 968519 in place), allowing me to ssh in and unlock the luks volume, but the error then shows up later in the boot process, preventing the OS from bringing up eth0 for regular use.
Logging in on the serial console and removing/reloading the dwmac_rk kernel module does get eth0 working, but that's obviously not a practical fix.
Based on a few test boots, it looks like the bug vanishes is less frequent when a scheduled fsck delays the boot process. Maybe there's a race condition in play? Maybe it's related to the issue underlying 968519 ?