[U-Boot] [PATCH 1/3 v2] 83xx: Default to using DMA to initialize SDRAM

Peter Tyser ptyser at xes-inc.com
Tue Jul 14 20:37:38 CEST 2009


On Tue, 2009-07-14 at 12:32 -0500, Kim Phillips wrote:
> On Tue, 14 Jul 2009 09:42:00 -0500
> Peter Tyser <ptyser at xes-inc.com> wrote:
> 
> 
> > I'm assuming Kim would prefer not to use DMA and thus this patch should
> > be discarded.
> 
> yeah, I prefer speed :)

It looked like Ira tested using the DDR controller for initialization
and it was ~4x as fast as the CPU method.  If someone out there in 83xx
land is looking to shave a few ms off their boot time (and they use ECC)
it shouldn't be that hard to add support for the
CONFIG_ECC_INIT_VIA_DDRCONTROLLER similar to the 85xx and 86xx
architectures.

> > Kim, let me know if this is the case and I'll resubmit a patch just to
> > fix the build error.  Patches 2 and 3 are still applicable even if we
> > discard patch 1.
> 
> ok
> 
> WD, please feel free to apply the fix, otherwise I'll have a pull
> request for you coming up.

I'll submit a patch just fixing the build error shortly.

Peter



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