Subject: Re: Accessing flash directly from User Space [SOLVED]

From: Gabriel Paubert <[email-masked]>
Date: Fri, 30 Oct 2009 18:49:04 +0100

On Fri, Oct 30, 2009 at 10:46:46AM -0600, Jonathan Haws wrote:
> > Michael Buesch wrote:
> > > Yes, I think the barrier is wrong.
> > > Please try with
> > >
> > > #define mb()	__asm__ __volatile__("eieio\n sync\n" : : :
> > "memory")
> > 
> > 
> > For uncached memory, eieio should be enough.
> 
> I tried eieio alone and it did not work.  It needed the above command to take care of it all.

Surprising. But sync is a superset of eieio, no?

In this case a sync alone should be sufficient (although an eieio
followed by a sync should not be much slower than a sync alone).

	Gabriel