Re: [PATCH v2 7/7] EmbeddedPkg: Fix DwEmmc read/write size in preparing DMA size

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

On Mon, May 27, 2019 at 05:30:28PM +0800, tien.hock.loh@intel.com wrote:
> From: "Tien Hock, Loh" <tien.hock.loh@intel.com>
> 
> Add support for reading data that is less than DWEMMC_BLOCK_SIZE,
> otherwise it would read bigger data than requested and cause errors
> 
> 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>
> 
> --
> v2:
> - Fix white space issue

Drop the version blurb from the commit message.
Below --- only.

> ---
>  EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> index b57833458f..ec2fa7923b 100644
> --- a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> +++ b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> @@ -493,7 +493,10 @@ PrepareDmaData (
>  
>    Cnt = (Length + DWEMMC_DMA_BUF_SIZE - 1) / DWEMMC_DMA_BUF_SIZE;
>    Blks = (Length + DWEMMC_BLOCK_SIZE - 1) / DWEMMC_BLOCK_SIZE;
> -  Length = DWEMMC_BLOCK_SIZE * Blks;
> +
> +  if(Length >= DWEMMC_BLOCK_SIZE) {
> +    Length = DWEMMC_BLOCK_SIZE * Blks;
> +  }
>  
>    for (Idx = 0; Idx < Cnt; Idx++) {
>      (IdmacDesc + Idx)->Des0 = DWEMMC_IDMAC_DES0_OWN | DWEMMC_IDMAC_DES0_CH |
> @@ -534,8 +537,14 @@ StartDma (
>    Data |= DWEMMC_IDMAC_ENABLE | DWEMMC_IDMAC_FB;
>    MmioWrite32 (DWEMMC_BMOD, Data);
>  
> -  MmioWrite32 (DWEMMC_BLKSIZ, DWEMMC_BLOCK_SIZE);
> -  MmioWrite32 (DWEMMC_BYTCNT, Length);
> +  if(Length < DWEMMC_BLOCK_SIZE) {
> +    MmioWrite32 (DWEMMC_BLKSIZ, Length);
> +    MmioWrite32 (DWEMMC_BYTCNT, Length);

There is still a duplicated line here

> +  }
> +  else {

} else {

> +    MmioWrite32 (DWEMMC_BLKSIZ, DWEMMC_BLOCK_SIZE);
> +    MmioWrite32 (DWEMMC_BYTCNT, Length);

and here

> +  }

Which could be outside of the conditional clause, since it is always
executed the same.

/
    Leif

>  }
>  
>  EFI_STATUS
> -- 
> 2.19.0
>