From: Greg KH <gregkh@linuxfoundation.org>
To: Matthias Brugger <matthias.bgg@gmail.com>
Cc: linux-kernel@vger.kernel.org, jslaby@suse.cz, heiko@sntech.de,
yingjoe.chen@gmail.com, ibanezchen@gmail.com,
linux-serial@vger.kernel.org
Subject: Re: [PATCH] tty: serial: 8250_mtk: Fix quot calculation
Date: Thu, 9 Oct 2014 14:52:28 -0700 [thread overview]
Message-ID: <20141009215228.GA23507@kroah.com> (raw)
In-Reply-To: <1412871811-5986-1-git-send-email-matthias.bgg@gmail.com>
On Thu, Oct 09, 2014 at 06:23:31PM +0200, Matthias Brugger wrote:
> The calculation of value quot for highspeed register set to three
> was wrong. This patch fixes the calculation so that the serial port
> for baudrates bigger then 576000 baud is working correctly.
>
> Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
> ---
> drivers/tty/serial/8250/8250_mtk.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> index 1c4b4bf..4376c48 100644
> --- a/drivers/tty/serial/8250/8250_mtk.c
> +++ b/drivers/tty/serial/8250/8250_mtk.c
> @@ -81,7 +81,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
> /* Set to highest baudrate supported */
> if (baud >= 1152000)
> baud = 921600;
> - quot = DIV_ROUND_CLOSEST(port->uartclk, 256 * baud);
> + quot = (port->uartclk / (256 * baud)) + 1;
> }
>
> /*
Has this always been incorrect, or was it caused by a specific patch?
Should it go to the stable kernels? If so, how far back?
thanks,
greg k-h
next prev parent reply other threads:[~2014-10-09 21:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-09 16:23 [PATCH] tty: serial: 8250_mtk: Fix quot calculation Matthias Brugger
2014-10-09 21:52 ` Greg KH [this message]
2014-10-10 8:10 ` Matthias Brugger
2014-10-20 11:30 ` Matthias Brugger
2014-11-06 3:27 ` Greg KH
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