Re: [PATCH 1/1] EmbeddedPkg/MmcDxe: Added MaxBlock Transfer Limit 65535 in R/W.

["Loh, Tien Hock" <tien.hock.loh@intel.com>]

Hi Ard,

I have checked the patch and it looks good.

However, I can no longer test the patch as the new DwMmc driver no longer uses the protocol.
Sorry for the delay, I initially thought I can test it until I investigated further today. 

Thanks 


> -----Original Message-----
> From: Pankaj Bansal <pankaj.bansal@nxp.com>
> Sent: Monday, April 27, 2020 2:19 PM
> To: Ard Biesheuvel <ard.biesheuvel@arm.com>; Leif Lindholm
> <leif@nuviainc.com>; Gaurav Jain <gaurav.jain@nxp.com>; Meenakshi
> Aggarwal <meenakshi.aggarwal@nxp.com>
> Cc: devel@edk2.groups.io; Haojian Zhuang <haojian.zhuang@linaro.org>; Loh,
> Tien Hock <tien.hock.loh@intel.com>; Varun Sethi <V.Sethi@nxp.com>
> Subject: RE: [PATCH 1/1] EmbeddedPkg/MmcDxe: Added MaxBlock Transfer
> Limit 65535 in R/W.
> 
> + Meenakshi
> 
> > -----Original Message-----
> > From: Ard Biesheuvel <ard.biesheuvel@arm.com>
> > Sent: Monday, April 6, 2020 7:42 PM
> > To: Leif Lindholm <leif@nuviainc.com>; Gaurav Jain
> > <gaurav.jain@nxp.com>
> > Cc: devel@edk2.groups.io; Pankaj Bansal <pankaj.bansal@nxp.com>;
> > Haojian Zhuang <haojian.zhuang@linaro.org>; Loh, Tien Hock
> > <tien.hock.loh@intel.com>
> > Subject: Re: [PATCH 1/1] EmbeddedPkg/MmcDxe: Added MaxBlock Transfer
> > Limit 65535 in R/W.
> >
> > On 4/6/20 4:08 PM, Leif Lindholm wrote:
> > > Hi Gaurav,
> > >
> > > Haojian, Tien Hock - can you help review/test this change?
> > >
> > > Best Regards,
> > >
> > > Leif
> > >
> > > On Fri, Apr 03, 2020 at 14:54:07 +0530, Gaurav Jain wrote:
> > >> Moved BlockCount calculation below BufferSize Validation checks.
> > >> First Ensure Buffersize is Not Zero and multiple of Media BlockSize.
> > >> then calculate BlockCount and perform Block checks.
> > >>
> > >> Corrected BlockCount calculation, as BufferSize is multiple of
> > >> BlockSize, So adding (BlockSize-1) bytes to BufferSize and then
> > >> divide by BlockSize will have no impact on BlockCount.
> > >>
> > >> Reading Large Images from MMC causes errors.
> > >> As per SD Host Controller Spec version 4.20, Restriction of 16-bit
> > >> Block Count transfer is 65535.
> > >> Max block transfer limit in single cmd is 65535 blocks.
> > >> Added Max Block check that can be processed is 0xFFFF.
> > >> then Update BlockCount on the basis of MaxBlock.
> > >>
> > >> Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
> >
> >
> > Hello Gaurav,
> >
> > Could you please elaborate on the underlying need for this change? If
> > you are considering using this driver for future NXP platforms, I
> > should point out that this legacy driver is only kept around for
> > existing users, and new users should use the driver stack in
> > MdeModulePkg, which is based on the UEFI spec.
> >
> > --
> > Ard.
> >
> >
> >