Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Date:   Sat, 7 Oct 2023 11:17:39 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Max Filippov <jcmvbkbc@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
        Jiri Slaby <jirislaby@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] serial: add PORT_ANY definition
Message-ID: <2023100706-circle-rework-993e@gregkh>
References: <20231006115713.801322-1-jcmvbkbc@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20231006115713.801322-1-jcmvbkbc@gmail.com>
Precedence: bulk

On Fri, Oct 06, 2023 at 04:57:13AM -0700, Max Filippov wrote:
> Current pattern in the linux kernel is that every new serial driver adds
> one or more new PORT_ definitions because uart_ops::config_port()
> callback documentation prescribes setting port->type according to the
> type of port found, or to PORT_UNKNOWN if no port was detected.
> 
> When the specific type of the port is not important to the userspace
> there's no need for a unique PORT_ value, but so far there's no suitable
> identifier for that case.
> 
> Provide generic port type identifier other than PORT_UNKNOWN for ports
> which type is not important to userspace.
> 
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> ---
>  include/uapi/linux/serial.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
> index 53bc1af67a41..070e50cf9e1e 100644
> --- a/include/uapi/linux/serial.h
> +++ b/include/uapi/linux/serial.h
> @@ -47,6 +47,8 @@ struct serial_struct {
>  /*
>   * These are the supported serial types.
>   */
> +/* Generic type identifier for ports which type is not important to userspace. */
> +#define PORT_ANY	(-1)

This should be at the end of the list.

And I think we need a better name, "PORT_GENERIC"?

thanks,

greg k-h