[PATCH 00/14] archosg9: add support for tablet

[Sascha Hauer]

On Wed, Oct 10, 2012 at 10:57:12AM +0200, vj wrote:
> On Wed, Oct 10, 2012 at 9:40 AM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> > On Tue, Oct 09, 2012 at 12:55:10AM +0200, Vicente wrote:
> >> This patch series is the same as before except for:
> >>  [PATCH 03/13] ARM: ensure irqs are disabled
> >>     imported irq handling from linux
> >>  [PATCH 07/13] uimage: improve transfer speed
> >>     solved a compile warning
> >
> > I applied most of this series, please check the result in the -next
> > branch.
> >
> 
> I'll check this week

Thanks.

> > Of course haven't applied this one
> >
> 
> It wasn't meant to be applied

I know, just thought I'd mention it anyway

> 
> >>   omap4: add usb boot source
> >>   bootm: close open files
> >
> >>   uimage: improve transfer speed
> >
> > Haven't applied this one as you haven't answered my question how
> > much improvement (and on which media) we get.
> 
> Yes, it's answered, see:
> http://lists.infradead.org/pipermail/barebox/2012-October/010208.html

Ups, missed that. That's really a huge speed gain. I wonder why this
happens. Maybe the overhead of request/release sdram region is
significant with MMU disabled. Could you play with the BUFSIZ parameter
to see if there's a good compromise between speeding up your transfer
and still sensible buffer sizes?

BTW I wonder if it would be possible to use the MMU in your setup. We
have a 1:1 flat mapping which should be no problem for the ROM code.
You probably would have to use dma_alloc_coherent to allocate the
buffers which are used for USB transfers.

Sascha


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