[U-Boot] [PATCH 2/3] mmc: sdhci: add the DMA select for SDMA

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi Rommel,

Thanks for report.

On 11/05/2012 10:39 PM, Rommel G Custodio wrote:
> Dear All, Jaehoon Chung
> 
> On 2012.09/21, Jaehoon Chung wrote:
>> In host-control register, DMA select bit field is present.
>> BUt in sdhci.c, didn't select for DMA.
> 
> This is an FYI.
> Maybe others will encounter the same problem I had.
> 
> This code has recently been mainlined and it has caused some problems in
> the IP that I am working with. The IP hangs when this code is enabled.
How did you hang your IP when this code is enabled?
Before enabled, also set to SDMA_MODE at HOST_CONTROL register.
Just More exactly  to set SDMA mode is used this code.
Is your IP using other DMA mode?
Just i want to know your hang case.

Best Regards,
Jaehoon Chung
> 
>> if set CONFIG_MMC_SDMA, we need to set SDMA-select bit.
> 
> The bit in the SDHCI specs show that 00b is the code for choosing SDMA.
> So this code is not really necessary as long as sdhci_init() or sdhci_set_ios(),
> the API that modifies SDHCI_HOST_CONTROL, does not touch the DMA bits. Right now,
> by looking at the code, sdhci_init() nor sdhci_set_ios() does not modify the DMA
> bits.
> 
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> 
> All the best,
> Rommel
>