Re: [PATCH] fix RTC_CLASS regression with PARISC

From: David Brownell
Date: Mon Sep 08 2008 - 15:13:49 EST

On Monday 08 September 2008, James Bottomley wrote:
> On Mon, 2008-09-08 at 11:19 -0700, David Brownell wrote:
> > On Monday 08 September 2008, James Bottomley wrote:
> > > Put it back again by making RTC_CLASS
> > > unselectable if the architecture is parisc.
> >
> > Easier if those distros just wouldn't select RTC_CLASS then. :)
> Yes, but think of distro config people rather like users ... if you can
> prevent them from doing something stupid, it's a good idea. In this
> case, there's currently no way anyone should ever select RTC_CLASS on
> parisc, so we should make that clear in the Kconfig file.

Preventing them from doing stupid stuff is exactly why we
have Kconfig prevent both legacy *AND* framework RTC code
from being selected. :)

Of course stupidity is infinite, and we didn't know about
this particular instance in advance...

> > And long term, better to work with RTC_CLASS. Eliminate that
> > crufty asm-parisc/rtc.h file and one more GEN_RTC user; and
> > share more widely-used infrastructure.
> >
> > If I read things right, that would be easy: the PARISC RTC is
> > two firmware calls, ptc_tod_{read,set}(), which would map to
> > RTC class {read,set}_time() methods of about six lines each.
> > The RTC framework can do UIE emulation, if needed.
> OK, I can look at that, but in the mean time could we make the option
> that causes the damage unselectable?

I'd worry if "the mean time" takes too long. But lacking a
PARISC laptop to fix this on, I'm unlikely to complain much.

> This is technically a regression
> because before your patch GEN_RTC would override RTC_CLASS, now it's the
> other way around.

Well, previously there was no override ... I think you mean
that parisc just completely ignored RTC_CLASS, treating it
like junk DNA.

- Dave
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