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Date:   Fri, 4 Aug 2023 22:44:17 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Tony Lindgren <tony@atomide.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>, Dhruva Gole <d-gole@ti.com>,
        Ilpo =?iso-8859-1?Q?J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>,
        John Ogness <john.ogness@linutronix.de>,
        Johan Hovold <johan@kernel.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Subject: Re: [PATCH] serial: 8250: Reinit port_id when adding back
 serial8250_isa_devs
Message-ID: <ZM1VET3hymOZEG4/@smile.fi.intel.com>
References: <20230804123546.25293-1-tony@atomide.com>
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On Fri, Aug 04, 2023 at 03:35:44PM +0300, Tony Lindgren wrote:
> After fixing the serial core port device to use port->port_id instead of
> port->line, unloading a hardware specific 8250 port driver started
> producing an error for "sysfs: cannot create duplicate filename".
> 
> This is happening as we are wrongly initializing port->port_id to zero
> when adding back serial8250_isa_devs instances, and the serial8250:0.0
> sysfs entry may already exist. For serial8250 devices, we typically have
> multiple devices mapped to a single driver instance. For the
> serial8250_isa_devs instances, the port->port_id is the same as port->line.
> 
> Let's fix the issue by re-initializing port_id when adding back the
> serial8250_isa_devs instances in serial8250_unregister_port().

Good catch and fix, thank you!
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko