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

[Jagan Teki]

On Thu, May 23, 2013 at 6:45 PM, Rajeshwari Shinde
<rajeshwari.s at samsung.com> 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) {

What is the inital value for host->fifoth_val, for the first time call.?

>                 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);
> --
> 1.7.4.4
>

Thanks,
Jagan.