[U-Boot] [RFC, PATCH] mmc: prepare SDHCI_HOST_CONTROL for SDMA operation

[Jaehoon Chung]

Hi Rommel,

Looks good to me. Thank you.

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

On 11/08/2012 06:46 AM, Rommel G Custodio wrote:
> modification for commit 804c7f422169212e92530e1ddaf74bf1ca9ebfa1
> 
> The original patch contained a bug.
> Using a char with sdhci_readl/sdhci_writel operation.
> The adjacent bytes to SDHCI_HOST_CONTROL (specially SDHCI_POWER_CONTROL)
> get mangled and can result in the controller entering an unstable state.
> 
> This patch also moves the process inside sdhci_init().
> 
> Signed-off-by: Rommel G Custodio <sessyargc at gmail.com>
> ---
>  drivers/mmc/sdhci.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
> index 7845f87..fae2169 100644
> --- a/drivers/mmc/sdhci.c
> +++ b/drivers/mmc/sdhci.c
> @@ -82,13 +82,6 @@ static int sdhci_transfer_data(struct sdhci_host *host, struct mmc_data *data,
>  				unsigned int start_addr)
>  {
>  	unsigned int stat, rdy, mask, timeout, block = 0;
> -#ifdef CONFIG_MMC_SDMA
> -	unsigned char ctrl;
> -	ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> -	ctrl &= ~SDHCI_CTRL_DMA_MASK;
> -	ctrl |= SDHCI_CTRL_SDMA;
> -	sdhci_writel(host, ctrl, SDHCI_HOST_CONTROL);
> -#endif
>  
>  	timeout = 1000000;
>  	rdy = SDHCI_INT_SPACE_AVAIL | SDHCI_INT_DATA_AVAIL;
> @@ -386,6 +379,14 @@ int sdhci_init(struct mmc *mmc)
>  {
>  	struct sdhci_host *host = (struct sdhci_host *)mmc->priv;
>  
> +#ifdef CONFIG_MMC_SDMA
> +	unsigned int ctrl;
> +	ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> +	ctrl &= ~SDHCI_CTRL_DMA_MASK;
> +	ctrl |= SDHCI_CTRL_SDMA;
> +	sdhci_writel(host, ctrl, SDHCI_HOST_CONTROL);
> +#endif
> +
>  	if ((host->quirks & SDHCI_QUIRK_32BIT_DMA_ADDR) && !aligned_buffer) {
>  		aligned_buffer = memalign(8, 512*1024);
>  		if (!aligned_buffer) {
>