From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: Re: [PATCH v2] serial: 8250_dw: support high baudrates if possible Date: Thu, 10 Jul 2014 22:11:58 -0500 Message-ID: <53BF55FE.9090500@linaro.org> References: <1404227734-14180-1-git-send-email-elder@linaro.org> <20140710231342.GA9557@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140710231342.GA9557@kroah.com> Sender: linux-kernel-owner@vger.kernel.org To: Greg KH Cc: heikki.krogerus@linux.intel.com, david.daney@cavium.com, loic.poulain@intel.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-serial@vger.kernel.org On 07/10/2014 06:13 PM, Greg KH wrote: > On Tue, Jul 01, 2014 at 10:15:34AM -0500, Alex Elder wrote: >> Currently the Synopsys DesignWare 8250 driver assumes its UART clock >> runs at a fixed rate. If a "real" clock was set up using the common >> clock framework, and that clock's rate is adjustable, it may be >> possible to support a wider range of baud rates by changing the >> UART clock rate. >> >> This is done by setting up a uart_port->set_termios method that >> requests a clock rate change if a different rate might make it >> more likely to achieve a specified baud. A new function >> dw8250_adjustable_clk() determines whether such clock rate >> adjustment is an option. >> >> Signed-off-by: Alex Elder >> --- >> v2: Limit clock changing to specific compatible devices. >> >> drivers/tty/serial/8250/8250_dw.c | 57 +++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 57 insertions(+) > > This no longer applies due to other changes in this driver. Can you > please refresh it against my tty-next branch of the tty.git tree and > resend? Interesting. Heikki seems to have generalized byt_set_termios() into dw8250_set_termios(), such that it's almost the same as what I did. I think I can just reuse it and simplify my patch considerably. But I'll do that in the morning... -Alex > thanks, > > greg k-h >