Re: [PATCH v2] serial: 8250_dw: support high baudrates if possible

[Alex Elder <elder@linaro.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 <elder@linaro.org>
>> ---
>> 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
>