From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Linmao Li <lilinmao@kylinos.cn>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Crescent Hsieh <crescentcy.hsieh@moxa.com>,
Lukas Wunner <lukas@wunner.de>,
Gerhard Engleder <gerhard@engleder-embedded.com>,
linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/3] serial: 8250_mxpcie: probe and console fixes
Date: Tue, 1 Sep 2026 12:01:11 +0300 [thread overview]
Message-ID: <apaUVwHNK39wjfF5@ashevche-desk.local> (raw)
In-Reply-To: <20260901041519.114737-1-lilinmao@kylinos.cn>
On Tue, Sep 01, 2026 at 12:15:16PM +0800, Linmao Li wrote:
> Three fixes for the Moxa PCIe serial driver, found by reading the code
> that was split out of 8250_pci.c and extended during the 7.3 merge
> window. That code is in mainline now but has not been in a released
> kernel, so the series is against tty-linus.
>
> Patch 1 fixes a NULL pointer dereference during probe: the serial core
> calls ->rs485_config() from within serial8250_register_8250_port(),
> before pci_set_drvdata() has published the board. It takes a board
> without RS232 support and SER_RS485_ENABLED still set once
> uart_get_rs485_mode() has run - on Crescent's ACPI machine the firmware
> node clears that flag, which is why it does not crash there.
>
> Patch 2 makes removal unregister only the ports that were registered.
> v1 failed the probe instead; as Andy pointed out that is a behavioural
> change, and keeping the ports that do work is what pciserial_init_ports()
> in 8250_pci.c does, so v2 keeps it and restores only the missing count.
>
> Patch 3 stops set_termios() from dereferencing port->state->port.tty,
> which is NULL when the serial core sets the line up for a console or for
> kgdboc.
>
> I have no Moxa board here. Crescent Hsieh tested patch 3 with kgdboc on
> a CP-168EL-A, and looked for patch 1's crash on a CP-134EL-A; the rest is
> compile-tested only, W=1 allmodconfig build of drivers/tty/serial/8250/
> and checkpatch --strict, both clean.
LGTM
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-09-01 9:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 4:15 [PATCH v2 0/3] serial: 8250_mxpcie: probe and console fixes Linmao Li
2026-09-01 4:15 ` [PATCH v2 1/3] serial: 8250_mxpcie: set the driver data before registering ports Linmao Li
2026-09-01 4:32 ` sashiko-bot
2026-09-01 5:31 ` Jiri Slaby
2026-09-01 4:15 ` [PATCH v2 2/3] serial: 8250_mxpcie: only unregister the ports that were registered Linmao Li
2026-09-01 4:27 ` sashiko-bot
2026-09-01 9:00 ` Andy Shevchenko
2026-09-01 4:15 ` [PATCH v2 3/3] serial: 8250_mxpcie: take the line settings from the new termios Linmao Li
2026-09-01 4:23 ` sashiko-bot
2026-09-01 5:33 ` Jiri Slaby
2026-09-01 9:01 ` Andy Shevchenko [this message]
2026-09-02 2:22 ` [PATCH v2 0/3] serial: 8250_mxpcie: probe and console fixes Crescent Hsieh
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