> > On Tue, Oct 27, 2009 at 04:24:53PM -0600, Jonathan Haws wrote:
> > >> >>> How can I get that pointer? Unfortunately I cannot simply
> > use
> > >> the
> > >> >>>
> > >> >> address of the flash. Is there some magical function call
> > that
> > >> >> gives me access to that portion of the memor
>
> > > On Tue, Oct 27, 2009 at 04:24:53PM -0600, Jonathan Haws wrote:
> > > >> >>> How can I get that pointer? Unfortunately I cannot simply
> > > use
> > > >> the
> > > >> >>>
> > > >> >> address of the flash. Is there some magical function call
> > > that
> > > >> >> gives me access to that po
>
> >
> > > > On Tue, Oct 27, 2009 at 04:24:53PM -0600, Jonathan Haws wrote:
> > > > >> >>> How can I get that pointer? Unfortunately I cannot simply
> > > > use
> > > > >> the
> > > > >> >>>
> > > > >> >> address of the flash. Is there some magical function call
> > > > that
> > > > >> >> gives
On Thu, 2009-10-29 at 10:00 +0100, Joakim Tjernlund wrote:
> >
> > > > On Tue, Oct 27, 2009 at 04:24:53PM -0600, Jonathan Haws wrote:
> > > > >> >>> How can I get that pointer? Unfortunately I cannot simply
> > > > use
> > > > >> the
> > > > >> >>>
> > > > >> >> address of the flash. Is there som
> Does O_DIRECT help? (you may need to define _GNU_SOURCE before
> #include)
Nope, O_DIRECT did not help - in fact it caused the application to crash. Why
that is I am not sure, but it crashed.
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.o
> > > Anyway, to make a long story short, I inserted an msync() after
> each
> > > assignment to the flash. This resolved my problem and I can now
> program my flash.
> >
> > Ouch, this was news to me too. Calling msync() after every write
> kills performance.
> > We use mmap(/dev/mem) to access H
On Thu, Oct 29, 2009 at 10:00:28AM +0100, Joakim Tjernlund wrote:
> > I have found the problem. It occurred to me in the shower (okay not really,
> > but most good ideas happen there).
> >
> > What was happening is that I was in fact able to write to the correct
> > registers. However, I would tr
> On Thu, Oct 29, 2009 at 10:00:28AM +0100, Joakim Tjernlund wrote:
> > > I have found the problem. It occurred to me in the shower (okay
> not really,
> > > but most good ideas happen there).
> > >
> > > What was happening is that I was in fact able to write to the
> correct
> > > registers. How
On Friday 30 October 2009 15:50:22 Jonathan Haws wrote:
> > I suspect that the msync() was merely serving as a very heavyweight
> > memory barrier.
>
> I did try hacking the mb() calls from the kernel source to use them in user
> space, but they had no effect. I still had to include the calls to
> On Friday 30 October 2009 15:50:22 Jonathan Haws wrote:
> > > I suspect that the msync() was merely serving as a very
> heavyweight
> > > memory barrier.
> >
> > I did try hacking the mb() calls from the kernel source to use
> them in user space, but they had no effect. I still had to include
>
> asm("eieio; sync");
Hmm...
: : : "memory"
And, doesn't ";" start a comment in assembly? (no, not on powerpc it seems)
Just to make sure, if you replace msync() with another system call,
like "kill(1, 0);" you can verify wether it's really useful or if it's
only acting as a barrier.
/a
On Friday 30 October 2009 16:08:55 Alessandro Rubini wrote:
> > asm("eieio; sync");
>
> Hmm...
> : : : "memory"
>
> And, doesn't ";" start a comment in assembly? (no, not on powerpc it seems)
Yes, I think the barrier is wrong.
Please try with
#define mb()__asm__ __volatile__("eieio\n
> On Friday 30 October 2009 16:08:55 Alessandro Rubini wrote:
> > > asm("eieio; sync");
> >
> > Hmm...
> > : : : "memory"
> >
> > And, doesn't ";" start a comment in assembly? (no, not on powerpc
> it seems)
>
> Yes, I think the barrier is wrong.
> Please try with
>
> #define mb() __asm__ __
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.
Micha
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlab
On Fri, Oct 30, 2009 at 04:08:55PM +0100, Alessandro Rubini wrote:
> > asm("eieio; sync");
>
> Hmm...
> : : : "memory"
>
> And, doesn't ";" start a comment in assembly? (no, not on powerpc it seems)
';' is an instruction separator on all GNU as targets that I'm familiar
with (though a quic
> 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
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.
>
> > On Friday 30 October 2009 16:08:55 Alessandro Rubini wrote:
> > > > asm("eieio; sync");
> > >
> > > Hmm...
> > >: : : "memory"
> > >
> > > And, doesn't ";" start a comment in assembly? (no, not on powerpc
> > it seems)
> >
> > Yes, I think the barrier is wrong.
> > Please try with
> >
> >
On Saturday 31 October 2009 14:26:48 Joakim Tjernlund wrote:
> >
> > > On Friday 30 October 2009 16:08:55 Alessandro Rubini wrote:
> > > > > asm("eieio; sync");
> > > >
> > > > Hmm...
> > > >: : : "memory"
> > > >
> > > > And, doesn't ";" start a comment in assembly? (no, not on powerpc
> > > i
Michael Buesch wrote on 31/10/2009 17:42:54:
>
> On Saturday 31 October 2009 14:26:48 Joakim Tjernlund wrote:
> > >
> > > > On Friday 30 October 2009 16:08:55 Alessandro Rubini wrote:
> > > > > > asm("eieio; sync");
> > > > >
> > > > > Hmm...
> > > > >: : : "memory"
> > > > >
> > > > > And, do
On Saturday 31 October 2009 21:14:07 Joakim Tjernlund wrote:
> Michael Buesch wrote on 31/10/2009 17:42:54:
> >
> > On Saturday 31 October 2009 14:26:48 Joakim Tjernlund wrote:
> > > >
> > > > > On Friday 30 October 2009 16:08:55 Alessandro Rubini wrote:
> > > > > > > asm("eieio; sync");
> > > > >
Michael Buesch wrote on 31/10/2009 21:35:31:
>
> On Saturday 31 October 2009 21:14:07 Joakim Tjernlund wrote:
> > Michael Buesch wrote on 31/10/2009 17:42:54:
> > >
> > > On Saturday 31 October 2009 14:26:48 Joakim Tjernlund wrote:
> > > > >
> > > > > > On Friday 30 October 2009 16:08:55 Alessand
mmio[0] = address;
mmio[1] = data;
mb();
eieio is enough here.
mmio[3] |= 0x01; /* This triggers an operation -> address=data */
/* probably also need an mb() here, if the following code
* depends on the operation to be triggered. */
No, a sync does not guarantee the device has seen the sto
23 matches
Mail list logo
