Re: [PATCH] EmbeddedPkg/MmcDxe: Correct argument of ECSD read

[Leif Lindholm <leif.lindholm@linaro.org>]

On Thu, Jun 29, 2017 at 05:02:05PM +0800, Jun Nie wrote:
> The argument of CMD8 should be stuff bits according to standard
> JESD84-A44.

OK, I realise that "stuff bits" is a term used by the spec, so that is
probably sufficient explanation even though the term was known to me.
And the MdeModulePkg driver seems to agree on the technical point.
My question is why zeroes is the correct "stuff bits" value?

> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jun Nie <jun.nie@linaro.org>
> ---
>  EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
> index 4ce0ddd..c28207e 100644
> --- a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
> +++ b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
> @@ -210,7 +210,7 @@ EmmcIdentificationMode (
>    }
>  
>    // Fetch ECSD
> -  Status = Host->SendCommand (Host, MMC_CMD8, RCA);
> +  Status = Host->SendCommand (Host, MMC_CMD8, 0);
>    if (EFI_ERROR (Status)) {
>      DEBUG ((EFI_D_ERROR, "EmmcIdentificationMode(): ECSD fetch error, Status=%r.\n", Status));
>    }
> -- 
> 1.9.1
>