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

Ira W. Snyder iws at ovro.caltech.edu
Thu Jul 9 00:31:29 CEST 2009


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?

Other than the speed, I can confirm that it works as expected on my
8349emds-based board. I see no reason why there would be a problem on
the mpc8349emds, though I cannot test on the eval board itself. I do not
have an ECC SDRAM module.

Ira


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