Re: [RFC PATCH] tty: serial: Add 8250-core based omap driver

From: Felipe Balbi
Date: Thu Jul 03 2014 - 10:08:34 EST


On Thu, Jul 03, 2014 at 08:34:44AM -0500, Robert Nelson wrote:
> On Thu, Jul 3, 2014 at 8:25 AM, Felipe Balbi <balbi@xxxxxx> wrote:
> > On Thu, Jul 03, 2014 at 12:34:11AM -0700, Tony Lindgren wrote:
> >> * Robert Nelson <robertcnelson@xxxxxxxxx> [140702 12:27]:
> >> > On Wed, Jul 2, 2014 at 2:09 PM, Aaro Koskinen <aaro.koskinen@xxxxxx> wrote:
> >> > > Hi,
> >> > >
> >> > > On Wed, Jul 02, 2014 at 11:09:32AM -0500, Felipe Balbi wrote:
> >> > >> > It has been only tested as console UART.
> >> > >> > The tty name is ttyS based instead of ttyO. How big is the pain here,
> >> > >> > what could be the easiest way to provide compatibility?
> >> > >>
> >> > >> have been considering that myself for months. You could pass an optional
> >> > >> argument to serial8250_register_8250_port() but that only solves part of
> >> > >> the problem :-(
> >>
> >> Some kind of compability layer sure would be nice.
> >>
> >> > > When ttyS -> ttyO change was done on OMAP, compatibility was not an issue.
> >> > > Why should we care about it now?
> >> >
> >> > It would be a good opportunity to force everyone to update their bootloader. ;)
> >> >
> >> > Besides the BeagleBoard forum is quiet now, no one is complaining
> >> > about that old (ttyS -> ttyO) transition anymore..
> >>
> >> How about a Kconfig option to provide ttyO by default? The not even
> >> do that if kernel has cmdline option nottyomap.
> >
> > what about single zImage ? I don't want to use ttyO on my
> > Allwinner/Exynos/Snapdragon/whatever SoC just because OMAP is in the
> > same image ;-)
>
> What if we just kept it simple, leave the ttyO driver enabled and add
> a warning (pr_info) that it's deprecated. It's not like it's broken,
> it just won't get later features or devices support added.

Fine by me, I'd switch to 8250 as soon as it's merged though :-) would
be nice to get an example DTS change just so I can start testing on the
boards I have around.

--
balbi

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