Re: [patch 2.6.29-rc2] palm_bk3710 buildfix

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Monday 19 January 2009, Sergei Shtylyov wrote:
> Hello, I wrote:
> 
> >>>> Someone should fix hw_regs_t to neither be a typedef, nor
> >>>> use "unsigned long" where it should use "void __iomem *".
> >>>>       
> >>>     It cannot use pointers of course -- as the addresses can be I/O 
> >>> ports.
> >>>     
> >>
> >> It could use the ioread*() calls, which take pointers
> >> and handle both types of I/O in a type-safe manner.
> >>   
> >
> >   Probably they can... though using those would only slow down 
> > register access on x86.
> 
>    ... and cause code bloat due to switching to real function calls from 
> inlines which now should render into in/out isns.

OTOH it would allow to unify a lot of 'if (hwif->host_flags & IDE_HFLAG_MMIO)'
cases so the code may even shrink.  I also suspect that register access slow
down is most likely negligable (we can always measure and check it).

The real reason for not using ioread*() and co. is that not all archs support
them (though I checked some time ago, maybe they do now?) and we don't want to
break IDE support for them.

Thanks,
Bart