Re: [PATCH v2 6/7] EmbeddedPkg: Fix DwEmmc SendCommand polling

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

+Haojian,

Haojian - since you are the original author, can you comment on the
delays? Are these silicon bug workarounds (so we need to add a Pcd),
or does these changes work on your platforms too?

Regards,

Leif

On Mon, May 27, 2019 at 05:30:27PM +0800, tien.hock.loh@intel.com wrote:
> From: "Tien Hock, Loh" <tien.hock.loh@intel.com>
> 
> Change SendCommand polling mode to remove unnecessary delay, and check
> for transfer done only when block data is to be read/write. This would
> also increase performance slightly.
> 
> Signed-off-by: "Tien Hock, Loh" <tien.hock.loh@intel.com>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c | 43 +++++++++++++++-----
>  1 file changed, 33 insertions(+), 10 deletions(-)
> 
> diff --git a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> index c6c8e04917..b57833458f 100644
> --- a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> +++ b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> @@ -286,16 +286,13 @@ SendCommand (
>              DWEMMC_INT_RCRC | DWEMMC_INT_RE;
>    ErrMask |= DWEMMC_INT_DCRC | DWEMMC_INT_DRT | DWEMMC_INT_SBE;
>    do {
> -    MicroSecondDelay(500);
>      Data = MmioRead32 (DWEMMC_RINTSTS);
> -
> -    if (Data & ErrMask) {
> -      return EFI_DEVICE_ERROR;
> -    }
> -    if (Data & DWEMMC_INT_DTO) {     // Transfer Done
> -      break;
> -    }
>    } while (!(Data & DWEMMC_INT_CMD_DONE));
> +
> +  if (Data & ErrMask) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
>    return EFI_SUCCESS;
>  }
>  
> @@ -550,8 +547,9 @@ DwEmmcReadBlockData (
>    )
>  {
>    EFI_STATUS  Status;
> -  UINT32      DescPages, CountPerPage, Count;
> +  UINT32      DescPages, CountPerPage, Count, ErrMask;
>    EFI_TPL     Tpl;
> +  UINTN Rintsts = 0;
>  
>    Tpl = gBS->RaiseTPL (TPL_NOTIFY);
>  
> @@ -574,6 +572,18 @@ DwEmmcReadBlockData (
>      DEBUG ((DEBUG_ERROR, "Failed to read data, mDwEmmcCommand:%x, mDwEmmcArgument:%x, Status:%r\n", mDwEmmcCommand, mDwEmmcArgument, Status));
>      goto out;
>    }
> +
> +  while(!((MmioRead32(DWEMMC_RINTSTS) & (DWEMMC_INT_DTO)))) {
> +    Rintsts = MmioRead32 (DWEMMC_RINTSTS);
> +  }
> +  ErrMask = DWEMMC_INT_EBE | DWEMMC_INT_HLE | DWEMMC_INT_RTO |
> +            DWEMMC_INT_RCRC | DWEMMC_INT_RE | DWEMMC_INT_DCRC |
> +            DWEMMC_INT_DRT | DWEMMC_INT_SBE;
> +
> +  if (Rintsts & ErrMask) {
> +    Status = EFI_DEVICE_ERROR;
> +    goto out;
> +  }
>  out:
>    // Restore Tpl
>    gBS->RestoreTPL (Tpl);
> @@ -589,8 +599,9 @@ DwEmmcWriteBlockData (
>    )
>  {
>    EFI_STATUS  Status;
> -  UINT32      DescPages, CountPerPage, Count;
> +  UINT32      DescPages, CountPerPage, Count, ErrMask;
>    EFI_TPL     Tpl;
> +  UINTN Rintsts = 0;
>  
>    Tpl = gBS->RaiseTPL (TPL_NOTIFY);
>  
> @@ -613,6 +624,18 @@ DwEmmcWriteBlockData (
>      DEBUG ((DEBUG_ERROR, "Failed to write data, mDwEmmcCommand:%x, mDwEmmcArgument:%x, Status:%r\n", mDwEmmcCommand, mDwEmmcArgument, Status));
>      goto out;
>    }
> +
> +  while(!((MmioRead32(DWEMMC_RINTSTS) & (DWEMMC_INT_DTO)))) {
> +    Rintsts = MmioRead32 (DWEMMC_RINTSTS);
> +  }
> +  ErrMask = DWEMMC_INT_EBE | DWEMMC_INT_HLE | DWEMMC_INT_RTO |
> +            DWEMMC_INT_RCRC | DWEMMC_INT_RE | DWEMMC_INT_DCRC |
> +            DWEMMC_INT_DRT | DWEMMC_INT_SBE;
> +
> +  if (Rintsts & ErrMask) {
> +    Status = EFI_DEVICE_ERROR;
> +    goto out;
> +  }
>  out:
>    // Restore Tpl
>    gBS->RestoreTPL (Tpl);
> -- 
> 2.19.0
>