[U-Boot] [PATCH v7 5/9] arm: serial: Add ability to use pre-initialized UARTs

[Simon Glass]

Hi Tom,

On 16 October 2015 at 18:23, Tom Rini <trini at konsulko.com> wrote:
> On Fri, Oct 16, 2015 at 04:27:31PM -0600, Simon Glass wrote:
>> Hi Linus,
>>
>> On 16 October 2015 at 15:23, Linus Walleij <linus.walleij at linaro.org> wrote:
>> > On Wed, Oct 14, 2015 at 6:55 PM, Sergey Temerkhanov
>> > <s.temerkhanov at gmail.com> wrote:
>> >
>> >> On some systems, UART initialization is performed before running U-Boot.
>> >> This commit allows to skip UART re-initializaion on those systems
>> >>
>> >> Signed-off-by: Sergey Temerkhanov <s.temerkhanov at gmail.com>
>> >> Signed-off-by: Radha Mohan Chintakuntla <rchintakuntla at cavium.com>
>> >>
>> >> Reviewed-by: Simon Glass <sjg at chromium.org>
>> > (...)
>> >
>> >> diff --git a/doc/device-tree-bindings/serial/pl01x.txt b/doc/device-tree-bindings/serial/pl01x.txt
>> >> index 61c27d1..0591497 100644
>> >> --- a/doc/device-tree-bindings/serial/pl01x.txt
>> >> +++ b/doc/device-tree-bindings/serial/pl01x.txt
>> >> @@ -5,3 +5,6 @@ Required properties:
>> >>  - reg: exactly one register range with length 0x1000
>> >>  - clock: input clock frequency for the UART (used to calculate the baud
>> >>    rate divisor)
>> >> +
>> >> +Optional properties:
>> >> +- u-boot,skip-init: skip UART initialization at start.
>> >
>> > Again: get this merged in the Linux kernel FIRST. Is it?
>>
>> We had a little bit of a chat about this at ELCE. It would be great to
>> get these changes merged with the kernel but the amount of
>> push-back/energy it requires is still excessive IMO. Any thoughts?
>
> But it also requires that we try.  Did we try here?  My first thought is
> that there's a number of things it would be nice to say "don't re-init
> stuff" to the kernel as well.

See the thread that ends here:

http://lists.denx.de/pipermail/u-boot/2015-July/219283.html

Regards,
Simon