[PATCH 3/3] serial: pl011: allow very high baudrates

[Russell King - ARM Linux]

On Fri, Sep 21, 2012 at 03:37:10PM +0100, Alan Cox wrote:
> > Device drivers should use c_[io]speed directly!
> > 
> > Alan Cox wrote this, so Alan: should I just ditch the use of
> > uart_get_baud_rate() and program the divider directly from
> > c_[io]speed?
> 
> Yes.
> 
> The functions are designed to act as helpers for old devices. In fact
> we can actually probably abolish tty_termios_baud_rate at this point as
> I don't think there is much if anything left which blows up fed a non
> Bxxx table entry.
> 
> I will have a look at that in fact see what it involves at this point.

Alan - the only issue that remains is handling the invalid baud rate
situation - if left to individual drivers to do this, we will see them
doing stuff (as was the case with this very patch - and was the case
prior to serial_core) such as using dev_err() to print an error and
merely returning from their set_termios function, or clamping to some
speed and not feeding back to userspace what they're actually doing.