Subject: [PATCH 2/3] tty/serial: of_serial: add support for PXA/MMP uarts

From: [email-masked] (Peter Hurley)
Date: Fri, 30 Jan 2015 15:24:08 -0500

On 01/30/2015 02:51 PM, Rob Herring wrote:
> On Wed, Jan 28, 2015 at 11:37 AM, Peter Hurley <[email-masked]> wrote:
>> On 01/27/2015 11:44 AM, Rob Herring wrote:
>>> On Tue, Jan 27, 2015 at 9:09 AM, Peter Hurley <[email-masked]> wrote:
>>
>> [...]
>>
>>>> Maybe Kconfig should warn if they're both built-in or both modules?
>>>
>>> Is there a way to do that?
>>
>> Well, it's not what I had in mind originally, but the diff below
>> generates a broken dependencies warning without causing build problems:
>>         $ scripts/kconfig/mconf Kconfig
>>         warning: (SERIAL_PXA) selects TTYS_DRIVER_PXA which has unmet direct dependencies (TTY && HAS_IOMEM && !TTYS_DRIVER)
>>
>> (My original idea was thwarted by the requirement that choice/endchoice
>> requires prompts).
> 
> Okay, but this should be a separate patch. The problem exists with or
> without my patch.

Yeah, don't worry about this. The solution of how to deal with multiple
ttyS drivers needs to address this problem.

>> That said, for PXA, I think we agree splitting out a standalone 8250 platform
>> driver is the solution.
> 
> So after all the discussion, you are okay with the original patch?

With a more specific commit log, yes. At a minimum, noting under what
circumstances the 8250 driver replaces the pxa2xx-uart driver. (And maybe
noting that this doesn't break hardware that needs those workarounds in
pxa.c).

Regards,
Peter Hurley