linux-kernel - Re: [PATCH 6/6] tty: serial: amba-pl011: Parse bits option as 5, 6, 7 or 8 in _get

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Date:   Thu, 26 Oct 2023 10:53:29 -0400
From:   Hugo Villeneuve <hugo@...ovil.com>
To:     Théo Lebrun <theo.lebrun@...tlin.com>
Cc:     Russell King <linux@...linux.org.uk>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
        Linus Walleij <linus.walleij@...aro.org>,
        Gregory CLEMENT <gregory.clement@...tlin.com>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Vladimir Kondratiev <vladimir.kondratiev@...ileye.com>,
        Tawfik Bayouk <tawfik.bayouk@...ileye.com>
Subject: Re: [PATCH 6/6] tty: serial: amba-pl011: Parse bits option as 5, 6,
 7 or 8 in _get_options

On Thu, 26 Oct 2023 12:41:23 +0200
Théo Lebrun <theo.lebrun@...tlin.com> wrote:

Hi,
I would change the commit title to better indicate that you add support
for bits 5 and 6, which was missing.

Maybe "Add support for 5 and 6 bits in..." ?

> pl011_console_get_options() gets called to retrieve currently configured
> options from the registers. Previously, LCRH_TX.WLEN was being parsed

It took me some time to understand your explanation :) Maybe change
to:

"Previously, only 7 or 8 bits were supported."

> as either 7 or 8 (fallback). Hardware supports values from 5 to 8

Add bits:

"5 to 8 bits..."

And indicate that this patch adds support for 5 and 6 bits.


> inclusive, which pl011_set_termios() exploits for example.
> 
> Signed-off-by: Théo Lebrun <theo.lebrun@...tlin.com>
> ---
>  drivers/tty/serial/amba-pl011.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 5774d48c7f16..b2062e4cbbab 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2384,10 +2384,7 @@ static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
>  			*parity = 'o';
>  	}
>  
> -	if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
> -		*bits = 7;
> -	else
> -		*bits = 8;
> +	*bits = FIELD_GET(0x60, lcr_h) + 5; /* from 5 to 8 inclusive */

Capital "F" -> "From...".

And add "bits" -> "From 5 to 8 bits..."

Hugo.


>  
>  	ibrd = pl011_read(uap, REG_IBRD);
>  	fbrd = pl011_read(uap, REG_FBRD);
> 
> -- 
> 2.41.0
>