[U-Boot] [PATCH 0/3] DMA ECC update

[Ira W. Snyder <iws@ovro.caltech.edu>]

On Wed, Jul 08, 2009 at 03:31:29PM -0700, Ira W. Snyder wrote:
> On Wed, Jul 08, 2009 at 02:28:39PM -0500, Peter Tyser wrote:
> > These changes bring the 83xx SDRAM ECC initialization in line
> > with the 85xx/86xx boards and also fixes a minor bug in fsl_dma.c.
> > 
> > I don't have any 83xx boards to test on, so it would be appreciated
> > if someone with 83xx hardware that uses ECC could give the patches
> > a shot.
> > 
> > It'd be nice if SDRAM could be initialized via the DDR controller
> > with CONFIG_ECC_INIT_VIA_DDRCONTROLLER on the 83xx platform too,
> > but I'm not going to tackle it:)
> > 
> > The patches also resolve the compile error Stefan brought up with
> > non-freescale boards with CONFIG_ECC.
> > 
> > Peter Tyser (3):
> >   83xx: Default to using DMA to initialize SDRAM
> >   83xx: Added CONFIG_MEM_INIT_VALUE for boards with ECC
> >   fsl_dma: Fix SDRAM initial value
> > 
> 
> Something in this patch makes the ECC DDR initialization VERY slow. It
> used to take <5 seconds, now it takes ~20 seconds for the memory to
> initialize.
> 
> I wonder why the CPU method would be so much faster?
> 

As a further quick note, I just hacked in support for initializing the
DDR via the DDR controller. Nothing good for submission, but it works
fine for my board. (We're using fixed_sdram(), no SPD code).

The DDR controller takes about 3 seconds to initialize all 256MB of RAM
on the board.

Ira