Re: Boot stall regression from "printk for 5.19" merge

From: Daniel Palmer
Date: Mon Jun 20 2022 - 06:38:59 EST


Hi Marek,

On Mon, 20 Jun 2022 at 03:51, Marek Behún <kabel@xxxxxxxxxx> wrote:
>
> Hello Linus, Petr, John,
>
> the series
> https://lore.kernel.org/linux-kernel/YouKQw72H7y9EJQK@alley/
> merged by commit 537e62c865dc ("Merge tag 'printk-for-5.19' of
> git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux")
>
> and in particular the commit 09c5ba0aa2fc ("printk: add kthread console
> printers")
>
> causes a regression on arm64 (Marvell CN9130-CRB board) where the
> system boot freezes in most cases (and is unusable until restarted by
> watchdog), or, in some cases boots, but the console output gets mangled
> for a while (the serial console spits garbage characters).

FWIW I have seen a similar issue to this on a totally different
machine/board on arm (Sigmastar SSD202D, "mstarv7" in the kernel..)
since rebasing my tree on 5.19.
I don't see lock ups all the time but every few boots the machine will
deadlock. Usually with garbage as the last message on serial.
With both serial and a display as consoles on the command line I could
sometimes see more output on the display but I didn't manage to debug
it.
Adding quiet to the command line made it go away so I've been doing
that as workaround.

Serial driver in question is 8250_dw.c

Cheers,

Daniel