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To: Fushuai Wang <fushuai.wang@linux.dev>, gregkh@linuxfoundation.org,
 jirislaby@kernel.org, osama.abdelkader@gmail.com, jackzxcui1989@163.com,
 asrinivasan@oss.tenstorrent.com, andy.shevchenko@gmail.com,
 broonie@kernel.org
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Fushuai Wang
 <wangfushuai@baidu.com>
Subject: Re: [PATCH] Revert "serial: 8250: Clear CON_PRINTBUFFER on port
 re-registration"
In-Reply-To: <20260724072452.40455-1-fushuai.wang@linux.dev>
References: <20260724072452.40455-1-fushuai.wang@linux.dev>
Date: Fri, 24 Jul 2026 10:38:02 +0206
Message-ID: <874ihookjh.fsf@jogness.linutronix.de>
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On 2026-07-24, Fushuai Wang <fushuai.wang@linux.dev> wrote:
> From: Fushuai Wang <wangfushuai@baidu.com>
>
> This reverts commit d338ab1d90603f875c4f7ed223406535378173a5.
>
> This may cause some boot logs to be lost on some platforms.
>
> Reported-by: Mark Brown <broonie@kernel.org>
> Reported-by: Anirudh Srinivasan <asrinivasan@oss.tenstorrent.com>
> Link: https://lore.kernel.org/all/20260522101042.21976-1-fushuai.wang@linux.dev/
> Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>

Reviewed-by: John Ogness <john.ogness@linutronix.de>

I also recently stumbled on commmit d338ab1d9060 ("serial: 8250: Clear
CON_PRINTBUFFER on port re-registration") and was surprised to see it
was accepted.

If the double-printing is happening for certain cases with 8250_pnp, I
would expect 8250_pnp (not 8250_core) to detect and handle that
case. 8250_core is the base for a lot of 8250 variants.

John Ogness