Re: [PATCH] serial: rewrite pxa2xx-uart to use 8250_core

James Cameron
2013-12-06T09:54:11Z

On Fri, Dec 06, 2013 at 01:28:51PM +0400, Sergei Ianovich wrote:
> On Fri, 2013-12-06 at 00:17 +0000, Russell King - ARM Linux wrote:
>
> > I may be able to - one of the downsides though is that many of these
> > systems had hard-coded scripts which started a getty on the original
> > port - and that kind of makes it difficult to sort out. This kind of
> > change becomes very much one of Linus' "flag days".
>
> > So I'd suggest that we have a period where the old driver is still
> > available, so at least people can choose to use the old major/minor
> > numbers for a while.
>
> The patch doesn't change how the driver looks from the outside. The old
> driver was using 8250 name (ttyS), major (4) and first minor (64). So we
> only resolve an internal conflict.

I don't understand why /dev/ttyS2 (4,66) changed to /dev/ttyS0 (4,64)
after the patch was applied to olpc-kernel/arm-3.5 but, as you say it
doesn't change, perhaps there is something between 3.5 and now for me
to watch out for. My problem.

> Kernel configuration is the place where issues may appear, since the
> patch removes CONFIG_SERIAL_PXA_CONSOLE option. I've updated all
> in-kernel users. However, out-of-kernel configs will no longer provide
> serial console, unless manually reconfigured. Is this the case we should
> worry about?

OLPC holds an out-of-kernel config (xo_4_defconfig); but no, I don't
think we'd have trouble with this. Go for it.

--
James Cameron