Re: [PATCH v2] mmc: sdhci-of-esdhc: add workaround for pre divider initial value

[Joakim Tjernlund <joakim.tjernlund@transmode.se>]

On Tue, 2015-08-11 at 10:53 +0800, Yangbo Lu wrote:
> For eSDHC(version < 2.3), the pre divider only could divide base clock
> by 2 at least. Add workaround for this to avoid unexpected issue.
> 
> Signed-off-by: Yangbo Lu <yangbo.lu@freescale.com>
> ---
Thanks a lot, here is my:

Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>

>  drivers/mmc/host/sdhci-of-esdhc.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> index 797be75..653f335 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -208,6 +208,12 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
>  	if (clock == 0)
>  		return;
>  
> +	/* Workaround to start pre_div at 2 for VNN < VENDOR_V_23 */
> +	temp = esdhc_readw(host, SDHCI_HOST_VERSION);
> +	temp = (temp & SDHCI_VENDOR_VER_MASK) >> SDHCI_VENDOR_VER_SHIFT;
> +	if (temp < VENDOR_V_23)
> +		pre_div = 2;
> +
>  	/* Workaround to reduce the clock frequency for p1010 esdhc */
>  	if (of_find_compatible_node(NULL, NULL, "fsl,p1010-esdhc")) {
>  		if (clock > 20000000)