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From: Arnd Bergmann <arnd@arndb.de>
To: Richard Cochran <richardcochran@gmail.com>
Subject: Re: [PATCH V14 3/4] ptp: Added a clock driver for the IXP46x.
Date: Mon, 18 Apr 2011 10:21:01 +0200
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On Monday 18 April 2011, Richard Cochran wrote:
> On Mon, Apr 18, 2011 at 08:56:03AM +0200, Arnd Bergmann wrote:
> > On Monday 18 April 2011, Richard Cochran wrote:
> > > +
> > > +       lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
> > > +       hi = __raw_readl(&regs->channel[ch].src_uuid_hi);
> > > +
> > 
> > I guess you should use readl(), not __raw_readl() here. The __raw_* functions
> > are not meant for device drivers.
> 
> Krzysztof had a different opinion about this.
> 
>     https://lkml.org/lkml/2011/1/8/67
> 
> Anyway, it is his driver, and I just followed what he does elsewhere
> in the driver. It make sense to me to keep the driver consistent.
> Maybe we should make the change throughout?

It would certainly be useful to fix it up. I now realized that this driver
supports both big-endian and little-endian configurations, so just using
readl() is certainly broken.
There should probably be an ixp specific version of the safe I/O accessors
to deal with it on all on-chip peripherals in a safe way.

	Arnd