From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
To: "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>
CC: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "jslaby@suse.com" <jslaby@suse.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-snps-arc@lists.infradead.org" 
        <linux-snps-arc@lists.infradead.org>
Subject: Re: [PATCH v3] earlycon: initialise baud field of earlycon device
 structure
Thread-Topic: [PATCH v3] earlycon: initialise baud field of earlycon device
 structure
Thread-Index: AQHTGpms5MGrZgnQOEaKmleDb8Ec26KeZNsA
Date: Thu, 31 Aug 2017 13:33:56 +0000
Message-ID: <1504186436.15555.24.camel@synopsys.com>
References: <20170821162213.27102-1-Eugeniy.Paltsev@synopsys.com>
In-Reply-To: <20170821162213.27102-1-Eugeniy.Paltsev@synopsys.com>
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Hi,

Maybe you have any comments or remarks about this patch?
And if you don't could you please apply it.

Thanks.

On Mon, 2017-08-21 at 19:22 +0300, Eugeniy Paltsev wrote:
> For now baud field of earlycon structure device is't initialised at all
> in of_setup_earlycon (in oppositе to register_earlycon).
> 
> So when I use stdout-path to point earlycon device
> (like stdout-path = &serial or stdout-path = "serial:115200n8")
> baud field of earlycon device structure remains uninitialised and
> earlycon initialization is not performed correctly as
> of_setup_earlycon is used.
> When pass all arguments via bootargs
> (like bootargs = "earlycon=uart8250,mmio32,0xf0005000,115200n8")
> initialization is performed correctly as register_earlycon is used.
> 
> So initialise baud field of earlycon device structure by value of
> "current-speed" property from device tree or from options
> (if they exist) when we use of_setup_earlycon
> 
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
> ---
> Changes v2 -> v3:
>  * Use simple_strtoul instead of kstrtoul as with kstrtoul we can't parse
>    options string which includes arguments except baudrate (like "115200n8")
> 
> Changes v1 -> v2:
>  * Use standart property name "current-speed" instead of custom "baud"
> 
> NOTE:
> I don't add parsing of the other standard options here because we don't
> have any place to store them. When we parce and set options of the 'real'
> uart device (using uart_parse_options + uart_set_options) we populate
> ktermios structure an pass it to port->ops->set_termios callback of
> uart_port structure. So it is processing by uart driver itself. But we don't
> register such callbacks for earlycon. So we are only able to parse baud
> value, which can be stored in baud field of earlycon_device structure.
> 
>  drivers/tty/serial/earlycon.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
> index c365154..82e813b 100644
> --- a/drivers/tty/serial/earlycon.c
> +++ b/drivers/tty/serial/earlycon.c
> @@ -282,7 +282,12 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
>  		}
>  	}
>  
> +	val = of_get_flat_dt_prop(node, "current-speed", NULL);
> +	if (val)
> +		early_console_dev.baud = be32_to_cpu(*val);
> +
>  	if (options) {
> +		early_console_dev.baud = simple_strtoul(options, NULL, 0);
>  		strlcpy(early_console_dev.options, options,
>  			sizeof(early_console_dev.options));
>  	}
-- 
 Eugeniy Paltsev