Re: Debian parisc config for 2.6.26 broke the real time clock

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Mon, 2008-09-08 at 18:37 +0200, Bastian Blank wrote:
> On Sat, Sep 06, 2008 at 10:06:26AM -0500, James Bottomley wrote:
> > Parisc is a CONFIG_GEN_RTC architecture (we use the generic real time
> > clock driver).
> 
> Well.
> 
> >                 Starting with 2.6.26, debian is now enabling
> > CONFIG_RTC_CLASS (for platforms with specific RTC drivers) which
> > disables CONFIG_GEN_RTC and means that hwclock (and ntp tracking) are
> > broken on parisc with debian kernels 2.6.26 and above.
> 
> Yes. Most arches already needs it anyway.
> 
> > All of the arch/parisc/config files get this right, so someone at debian
> > must have screwed up somehow.  The config option CONFIG_RTC_CLASS must
> > be set to 'N' for all parisc systems.
> 
> Apparently hppa uses its special rtc type.  I propose that you take a
> look at drivers/rtc/rtc-ppc.c and write a wrapper rtc module.

That may be the way forwards depending on what the RTC developers say,
but it certainly won't fix the 2.6.26 regression.

> >                                        I'd suggest checking the debian
> > kernel configs against the in-tree default files to see if there are any
> > other cockups like this.
> 
> If there are, this are bugs in the kernel themself. I'm no hppa
> developer so I won't waste my time with such.

Hardly, the bug is actually in the debian configs.  You have
CONFIG_RTC_CLASS as a generic override.  This is wrong, it needs to be
subordinate to CONIFG_GEN_RTC.  The quick fix would be to move the
CONFIG_RTC_CLASS sequence down from generic to the architectures ... if
you're incapable of doing that, I might be able to find time to look at
doing it for you.

The real bug looks to be the debian config system which relies on
concatenation ... what's really needed is a way of turning
CONFIG_RTC_CLASS off on parisc while keeping RTC_CLASS generic for those
architectures that need it.

James