From: Greg KH <gregkh@linuxfoundation.org>
To: Matthias Brugger <matthias.bgg@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
jslaby@suse.cz, "Heiko Stübner" <heiko@sntech.de>,
"Yingjoe Chen" <yingjoe.chen@gmail.com>,
"Howard Chen" <ibanezchen@gmail.com>,
linux-serial@vger.kernel.org
Subject: Re: [PATCH] tty: serial: 8250_mtk: Fix quot calculation
Date: Wed, 5 Nov 2014 19:27:20 -0800 [thread overview]
Message-ID: <20141106032720.GA10803@kroah.com> (raw)
In-Reply-To: <CABuKBeL1v=E4ZSM2iq+zC2G=a1g4RT3DmJ16ra_RwQ_9ARZkZg@mail.gmail.com>
On Fri, Oct 10, 2014 at 10:10:45AM +0200, Matthias Brugger wrote:
> 2014-10-09 23:52 GMT+02:00 Greg KH <gregkh@linuxfoundation.org>:
> > 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?
>
> It has always been incorrect :o
>
> > Should it go to the stable kernels? If so, how far back?
>
> No need to go to the stable kernels. The driver is only in linux-next.
Well, it's in 3.18-rc1, so it should at least go into 3.18-final. I'll
queue it up for that.
thanks,
greg k-h
prev parent reply other threads:[~2014-11-06 3:27 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
2014-10-10 8:10 ` Matthias Brugger
2014-10-20 11:30 ` Matthias Brugger
2014-11-06 3:27 ` Greg KH [this message]
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