Date:   Thu, 30 Dec 2021 13:29:16 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Yu Tu <yu.tu@amlogic.com>
Cc:     linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        Jiri Slaby <jirislaby@kernel.org>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Vyacheslav <adeep@lexina.in>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: Re: [PATCH V3 2/6] tty: serial: meson: Request the register region
 in meson_uart_probe()
Message-ID: <Yc2mHOT4WwgUrrhG@kroah.com>
References: <20211230102110.3861-1-yu.tu@amlogic.com>
 <20211230102110.3861-3-yu.tu@amlogic.com>
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On Thu, Dec 30, 2021 at 06:21:06PM +0800, Yu Tu wrote:
> This simplifies resetting the UART controller during probe and will make
> it easier to integrate the common clock code which will require the
> registers at probe time as well.
> 
> Signed-off-by: Yu Tu <yu.tu@amlogic.com>
> ---
>  drivers/tty/serial/meson_uart.c | 24 ++++++------------------
>  1 file changed, 6 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
> index c9a37602ffd0..99efe62a1507 100644
> --- a/drivers/tty/serial/meson_uart.c
> +++ b/drivers/tty/serial/meson_uart.c
> @@ -397,24 +397,11 @@ static int meson_uart_verify_port(struct uart_port *port,
>  
>  static void meson_uart_release_port(struct uart_port *port)
>  {
> -	devm_iounmap(port->dev, port->membase);
> -	port->membase = NULL;
> -	devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
> +	/* nothing to do */
>  }

Are you sure a release call like this can be "empty"?  That goes against
the normal way the driver model works.  If it is empty, why have it at
all?

thanks,

greg k-h