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From:   Daniel Palmer <daniel@0x0f.com>
Date:   Mon, 20 Jun 2022 19:38:37 +0900
Message-ID: <CAFr9PXkVVYQ8+uxQF=42D7svnM95vzVoySv0pv22vH07m0VeNg@mail.gmail.com>
Subject: Re: Boot stall regression from "printk for 5.19" merge
To:     =?UTF-8?B?TWFyZWsgQmVow7pu?= <kabel@kernel.org>
Cc:     John Ogness <john.ogness@linutronix.de>,
        Petr Mladek <pmladek@suse.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Marek,

On Mon, 20 Jun 2022 at 03:51, Marek Beh=C3=BAn <kabel@kernel.org> 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