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

[Jaehoon Chung]

On 05/24/2013 03:27 AM, Jagan Teki wrote:
> 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.?
It should be set into board-specific file(dw-mmc_exynos.c) or others.

Best Regards,
Jaehoon Chung
> 
>>                 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.
>