Re: MMIO and gcc re-ordering issue

[Pantelis Antoniou]

On 28 ÎÎÏ 2008, at 11:36 ÎÎ, Haavard Skinnemoen wrote:

> Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote:
> > > > I'm happy to say that __raw is purely about ordering and make them
> > > > byteswap on powerpc tho (ie, make them little endian like the non- 
> > > > raw
> > > > counterpart).
> > >
> > > That would break a lot of drivers.
> >
> > How many actually use __raw_ * ?
>
> I do -- in all the drivers for on-chip peripherals that are shared
> between AT91 ARM (LE) and AVR32 (BE). Since everything goes on inside
> the chip, we must use LE accesses on ARM and BE accesses on AVR32.
>
> Currently, this is the only interface I know that can do native-endian
> accesses, so if you take it away, I'm gonna need an alternative
> interface that doesn't do byteswapping.
>
> Haavard

I certainly do too.

Quite a lot of SoC specific drivers use __raw for accessing their
on-chip peripherals.

Please don't change the __raw semantics, you'll end up breaking almost
everything that's BE.

-- Pantelis

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