[U-Boot] [PATCH] MMC: DWMMC: Fix FIFO_DEPTH calculation

[Jaehoon Chung]

Acked-by: Jaehoon Chung <jh80.chung at samsung.com>

On 05/23/2013 10:15 PM, Rajeshwari Shinde wrote:
> Current DWMMC driver used to give FIFO underrun/overrun error every 3rd time
> for mmc rescan command.
> In current code FIFO_DEPTH is getting calculated after reading the FIFOTH
> register and extracting the RX_WMARK bits from it i.e (RX_WMARK = FIFO_DEPTH/2 -1).
> Instead of storing the correct value, we were recalculating the FIFO_DEPT each
> time which is not correct.
> 
> Signed-off-by: Hatim Ali <hatim.rv at samsung.com>
> Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
> ---
>  drivers/mmc/dw_mmc.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
> index 4070d4e..be590a4 100644
> --- a/drivers/mmc/dw_mmc.c
> +++ b/drivers/mmc/dw_mmc.c
> @@ -332,11 +332,13 @@ static int dwmci_init(struct mmc *mmc)
>  	dwmci_writel(host, DWMCI_BMOD, 1);
>  
>  	fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
> -	if (host->fifoth_val)
> +	if (host->fifoth_val) {
>  		fifoth_val = host->fifoth_val;
> -	else
> +	} else {
>  		fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size/2 -1) |
>  			TX_WMARK(fifo_size/2);
> +		host->fifoth_val = fifoth_val;
> +	}
>  	dwmci_writel(host, DWMCI_FIFOTH, fifoth_val);
>  
>  	dwmci_writel(host, DWMCI_CLKENA, 0);
>