[U-Boot] [PATCH] powerpc/t1040qds: Add DDR Raw Timing support

York Sun yorksun at freescale.com
Wed Oct 30 17:43:40 CET 2013


On 10/25/2013 02:49 AM, Priyanka Jain wrote:
> T1040QDS-D3 has dual-rank DDR:
> 	Micron, MT18KSF51272AZ-1G6 (4GB, x72, CL=10).
> Add Raw Timing structure for this DDR.
> 
> Typically SPD method is used for getting DDR parameter
> and calculating values for various DDR controller registers.
> 
> But somentimes it may happen that SPD present on DDR may get
> accidently erased or is not working properly during initial
> bring-up. In that circumnstance, DDR raw timing structure can be
> use as fallback option for getting DDR parameters.
> 
> Signed-off-by: Poonam Aggrwal <poonam.aggrwal at freescale.com>
> Signed-off-by: Priyanka Jain <Priyanka.Jain at freescale.com>
> ---

I don't think it is appropriate to use raw timing for this application.
This board use DIMMs, not soldered DDR chips. In normal cases, this
piece of code is not used. It is only useful if you have a DIMM without
a valid SPD. You could get another DIMM. I am not saying this patch is
wrong, it is just useless for general public.

York




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