Re: [PATCH v6] serial: rewrite pxa2xx-uart to use 8250_core

From	Robert Jarzmik <robert.jarzmik@free.fr>
Newsgroups	linux.kernel
Subject	Re: [PATCH v6] serial: rewrite pxa2xx-uart to use 8250_core
Date	2016-02-22 08:20 +0100
Message-ID	<r4SWK-2a3-5@gated-at.bofh.it> (permalink)
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Sergei Ianovich <ynvich@gmail.com> writes:

> On Sat, 2016-02-06 at 22:22 -0800, Greg Kroah-Hartman wrote:
>> On Thu, Dec 24, 2015 at 06:15:14PM +0300, Sergei Ianovich wrote:
>> > pxa2xx-uart was a separate uart platform driver. It was declaring
>> > the same device names and numbers as 8250 driver. As a result,
>> > it was impossible to use 8250 driver on PXA SoCs.
>> > 
>> > Upon closer examination pxa2xx-uart turned out to be a clone of
>> > 8250_core driver.
>> > 
>> > Workaround for Erratum #19 according to Marvel(R) PXA270M Processor
>> > Specification Update (April 19, 2010) is dropped. 8250_core reads
>> > from FIFO immediately after checking DR bit in LSR.
>> > 
>> > The patch leaves the original SERIAL_PXA driver around. The
>> > original
>> > driver is just marked DEPRECATED in Kconfig and C source. When
>> > the original driver is considered safe to remove, no changes
>> > to SERIAL_8250 will be necessary.
>> 
>> But, you just broke existing configurations, right?  The serial port is
>> a different name now, are you willing to handle the angry users?
>
> No, the port name remains /dev/ttyS0. In fact, this conflict (both
> drivers use the same name and char major) is the reason for the patch.
> Noone should notice the change at runtime. There will be a warning at
> compile time which should make the transition to the new driver faster.
>
>> If so, great, get the platform maintainer to sign off on this please and
>> then resend it.

If you're talking about the PXA maintainer, then :
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>

I'm happy with the patch, all pxa board maintainers have been warned, and there
exists a fallback solution.

So let's go forward, and if people complain, let them complain and forward them
to me.

Cheers.

-- 
Robert

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Re: [PATCH v6] serial: rewrite pxa2xx-uart to use 8250_core Sergei Ianovich <ynvich@gmail.com> - 2016-02-22 03:00 +0100
  Re: [PATCH v6] serial: rewrite pxa2xx-uart to use 8250_core Robert Jarzmik <robert.jarzmik@free.fr> - 2016-02-22 08:20 +0100

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