[U-Boot] [PATCH 1/4] MMC: DWMMC: Modified fifo size computation

Simon Glass
2012-12-08T19:49:30Z

Hi Jaehoon,

On Wed, Dec 5, 2012 at 7:59 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> It looks good to me.
> Added minor comment.
>
> Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
>
> On 12/05/2012 10:31 PM, Amar wrote:
>> The current implementation of fifo size computation was giving improper
>> values for eMMC channel. Modified the computation as per user manual.
>>
>> Signed-off-by: Amarendra Reddy <amarendra.xt@samsung.com>
>> ---
>> drivers/mmc/dw_mmc.c | 2 ++
>> 1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
>> index 4070d4e..62dc152 100644
>> --- a/drivers/mmc/dw_mmc.c
>> +++ b/drivers/mmc/dw_mmc.c
>> @@ -332,6 +332,8 @@ static int dwmci_init(struct mmc *mmc)
>> dwmci_writel(host, DWMCI_BMOD, 1);
>>
>> fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
>> + fifo_size = ((fifo_size & RX_WMARK(0xFFF)) >> 16) + 1;
> How about using like FIFO_SIZE_MASK?

It might be better to avoid macros in header files which shift and
mask x, since they obscure the operation, and just define the amount
of shift and mask in the header file. Also if you have a #define for
the mask you should probably also have one for the shift, otherwise
you have the information in two places. So maybe:

#define RX_WMARK_SHIFT 16
#define RX_WMARK_MASK (0xfff << RX_WMARK_SHIFT)

fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1;

>> +
>> if (host->fifoth_val)
>> fifoth_val = host->fifoth_val;
>> else
>>
>
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Regards,
Simon