Re: [PATCH v4 01/11] MmcDxe: wait OCR busy bit free

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

On Tue, Nov 08, 2016 at 11:21:06PM +0800, Haojian Zhuang wrote:
> According to eMMC spec, OCR.PowerUp bit is also busy bit. If the busy
> bit is '0', CMD1 should be sent and OCR should be fetched again. And add
> a timeout counter on the repeated steps.
> 
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

I will wait for a final Tested-by: from Ryan, but from a code point of
view:
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

> ---
>  EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
> index 2d8038f..3f72b7f 100644
> --- a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
> +++ b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
> @@ -222,14 +222,19 @@ MmcIdentificationMode (
>  
>    // Send CMD1 to get OCR (MMC)
>    // This command only valid for MMC and eMMC
> -  Status = MmcHost->SendCommand (MmcHost, MMC_CMD1, EMMC_CMD1_CAPACITY_GREATER_THAN_2GB);
> -  if (Status == EFI_SUCCESS) {
> +  Timeout = MAX_RETRY_COUNT;
> +  do {
> +    Status = MmcHost->SendCommand (MmcHost, MMC_CMD1, EMMC_CMD1_CAPACITY_GREATER_THAN_2GB);
> +    if (EFI_ERROR (Status))
> +      break;
>      Status = MmcHost->ReceiveResponse (MmcHost, MMC_RESPONSE_TYPE_OCR, (UINT32 *)&OcrResponse);
>      if (EFI_ERROR (Status)) {
>        DEBUG ((EFI_D_ERROR, "MmcIdentificationMode() : Failed to receive OCR, Status=%r.\n", Status));
>        return Status;
>      }
> -
> +    Timeout--;
> +  } while (!OcrResponse.Ocr.PowerUp && (Timeout > 0));
> +  if (Status == EFI_SUCCESS) {
>      if (!OcrResponse.Ocr.PowerUp) {
>        DEBUG ((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD1): Card initialisation failure, Status=%r.\n", Status));
>        return EFI_DEVICE_ERROR;
> -- 
> 2.7.4
>