2017-06-29 20:09 GMT+08:00 Leif Lindholm <[email protected]>: > 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?
Yes, it is defined in page 2 in spec. I guess 0 is best filling value than other value when we do not need a real value. stuff bit: filling 0 bits to ensure fixed length frames for commands and responses. > >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Jun Nie <[email protected]> >> --- >> 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 >> _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
