RE: [PATCH v2] clocksource: Add BE APIs support for clocksource counter reading.

[Thomas Gleixner]

On Sun, 28 Sep 2014, Li.Xiubo@xxxxxxxxxxxxx wrote:
> > Subject: Re: [PATCH v2] clocksource: Add BE APIs support for clocksource
> > counter reading.
> > 
> > On Fri, 26 Sep 2014, Xiubo Li wrote:
> > > For now I just added  _be() support using ioread{16,32}be.
> > > And i have a check of the clocksource drivers, didn't find anyone
> > > using LE mode on one BE SoC, so _le() APIs is not needed.
> > 
> > Nonsense. The existing clocksource_mmio accessor function are
> > providing LE access independent of the CPU endianess. So we don't need
> > an _le() API simply because we have it already.
> > 
> > >  cycle_t clocksource_mmio_readl_up(struct clocksource *c)
> > >  {
> > > -	return (cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg);
> > > +	return (cycle_t)ioread32(to_mmio_clksrc(c)->reg);
> > 
> > And how exactly is this change related to adding BE support?
> > 
> 
> Actually not very much, since the _be() APIs are using ioread{16,32}be(),
> so I think using ioread{16,32}() will be less odd to having two different
> accessors here.
> 
> Wouldn't this be more unified somehow ?  

Changing existing code wants to be a separate patch with a proper
changelog and a proper argument WHY it needs to be changed in the
first place.

So please provide that separate patch first with a VERY REASONABLE
explanation in the changelog WHY the existing readl_relaxed() should
be replaced by ioread32().

Thanks,

	tglx
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