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From: Willy Tarreau <w@1wt.eu>
To: David Laight <David.Laight@ACULAB.COM>
Cc: "'Steven Rostedt'" <rostedt@goodmis.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Petr Mladek <pmladek@suse.com>,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	John Ogness <john.ogness@linutronix.de>
Subject: Re: Strange output on the console
Date: Fri, 25 Feb 2022 07:36:37 +0100	[thread overview]
Message-ID: <20220225063637.GA18039@1wt.eu> (raw)
In-Reply-To: <61226fc12ff9459d8daed8e346d6ab94@AcuMS.aculab.com>

On Fri, Feb 25, 2022 at 06:12:35AM +0000, David Laight wrote:
> From: Steven Rostedt
> > Sent: 25 February 2022 04:01
> > 
> > I've been noticing that my tests have been spitting out strange output on
> > the console. It would happen at boot up and then clear up. It looks like
> > something screwed up with the serial timing.
> > 
> > Attached is a dmesg of one of my test runs as an example.
> > 
> > I've noticed this on both 32 bit and 64 bit x86.
> > 
> > I haven't had time to look deeper into this, but I figured I let you know
> > about it.
> > 
> > And it always seems to happen right after:
> > 
> >   Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
> > 
> > Maybe this is a serial issue and not a printk one? :-/
> 
> Looks very much like the serial baud rate is being reset.

I don't think it's the baud rate, characters are still readable, it
looks more like a fifo being too short and causing lots of chars to
be dropped.

Willy

  reply	other threads:[~2022-02-25  6:37 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-25  4:00 Strange output on the console Steven Rostedt
2022-02-25  4:58 ` Sergey Senozhatsky
2022-02-25  5:07   ` Sergey Senozhatsky
2022-02-25 13:32     ` Steven Rostedt
2022-02-25 13:42       ` Steven Rostedt
2022-02-26  2:20         ` Sergey Senozhatsky
2022-02-26 11:49           ` Wander Costa
2022-02-28 16:05             ` Steven Rostedt
2022-03-02 18:49               ` Wander Costa
2022-02-25  6:12 ` David Laight
2022-02-25  6:36   ` Willy Tarreau [this message]
2022-02-25  9:37     ` John Ogness
2022-02-25  9:42       ` John Ogness
2022-02-25 10:11     ` David Laight
2022-02-25 10:32       ` Willy Tarreau
2022-02-25 11:11         ` David Laight
2022-02-25 12:25           ` Willy Tarreau
2022-02-25 13:03             ` David Laight
2022-02-25 13:17             ` Steven Rostedt
2022-02-25 13:25               ` Willy Tarreau
2022-02-25 13:28             ` Steven Rostedt
2022-02-25 13:40               ` Willy Tarreau
2022-02-25 13:44                 ` Steven Rostedt
2022-02-25 13:57                   ` Willy Tarreau
2022-02-25 13:53           ` Steven Rostedt

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