Russell King - ARM Linux wrote:
>
> On Tue, Apr 24, 2001 at 03:04:43AM -0700, Russ Dill wrote:
> > --- linux/Documentation/Configure.help Tue Apr 24 03:01:39 2001
> > +++ linux.curr/Documentation/Configure.help Tue Apr 24 02:55:11 2001
> > @@ -16802,8 +16802,9 @@
> > address divisible by 4. On 32-bit ARM processors, these non-aligned
> > fetch/store instructions will be emulated in software if you say
> > here, which has a severe performance impact. This is necessary for
> > - correct operation of some network protocols. With an IP-only
> > - configuration it is safe to say N, otherwise say Y.
> > + correct operation of some non-IP network protocols as well as the
> > + proper operation of mtd (Memory Technology Device Subsystem). If
> > + unsure, say Y here.
>
> If that is true, then we have a problem.
>
> I can imagine that some MTD chips would require a complete word to be written
> _in one write_ rather than several. I'd like to confirm why the MTD layer
> requires this before putting this in.
I confirmed with david that mtd does this, aparently, its an uncommon
case, so it doesn't have a large speed impact, and letting the trap
handle it is much simpler and less ugly than handling all the cases in
mtd (mutiple arch's, buswidth's, endianness, etc)
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