[U-Boot] [PATCH V2] MMC: DWMMC: Fix FIFO_DEPTH calculation

[Jaehoon Chung]

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

Thanks,
Jaehoon Chung

On 05/27/2013 05:32 AM, Simon Glass wrote:
> On Fri, May 24, 2013 at 5:45 AM, Rajeshwari Shinde <rajeshwari.s at samsung.com <mailto: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 default 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
> 
> 
> DEPTH
>  
> 
>     time which is not correct.
> 
>     Based on "[PATCH V9 3/9] DWMMC: Initialise dwmci and resolve EMMC read write issues"
>     http://permalink.gmane.org/gmane.comp.boot-loaders.u-boot/160247
> 
>     Signed-off-by: Hatim Ali <hatim.rv at samsung.com <mailto:hatim.rv at samsung.com>>
>     Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com <mailto:rajeshwari.s at samsung.com>>
> 
> 
> Acked-by: Simon Glass <sjg at chromium.org <mailto:sjg at chromium.org>>
> 
> Tested on pit using 'mmc rescan' and saw no problems now.
> 
> Tested-by: Simon Glass <sjg at chromium.org <mailto:sjg at chromium.org>>
>  
> 
>     ---
>     Changes in V2:
>             - remove fifoth_val local variable
>             - Rebased on top of "[PATCH V9 3/9] DWMMC: Initialise dwmci and resolve
>             EMMC read write issues".
>      drivers/mmc/dw_mmc.c |   14 ++++++--------
>      1 files changed, 6 insertions(+), 8 deletions(-)
> 
>     diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
>     index 1307b12..5da20ed 100644
>     --- a/drivers/mmc/dw_mmc.c
>     +++ b/drivers/mmc/dw_mmc.c
>     @@ -312,7 +312,7 @@ static void dwmci_set_ios(struct mmc *mmc)
>      static int dwmci_init(struct mmc *mmc)
>      {
>             struct dwmci_host *host = (struct dwmci_host *)mmc->priv;
>     -       u32 fifo_size, fifoth_val;
>     +       u32 fifo_size;
> 
>             dwmci_writel(host, DWMCI_PWREN, 1);
> 
>     @@ -332,15 +332,13 @@ static int dwmci_init(struct mmc *mmc)
>             dwmci_writel(host, DWMCI_IDINTEN, 0);
>             dwmci_writel(host, DWMCI_BMOD, 1);
> 
>     -       fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
>     -       fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1;
>     -       if (host->fifoth_val) {
>     -               fifoth_val = host->fifoth_val;
>     -       } else {
>     -               fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size / 2 - 1) |
>     +       if (!host->fifoth_val) {
>     +               fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
>     +               fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1;
>     +               host->fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size / 2 - 1) |
>                             TX_WMARK(fifo_size / 2);
>             }
>     -       dwmci_writel(host, DWMCI_FIFOTH, fifoth_val);
>     +       dwmci_writel(host, DWMCI_FIFOTH, host->fifoth_val);
> 
>             dwmci_writel(host, DWMCI_CLKENA, 0);
>             dwmci_writel(host, DWMCI_CLKSRC, 0);
>     --
>     1.7.4.4
> 
>