Re: ARM: dts: exynos: Properly select eMMC HighSpeed mode

[Alim Akhtar]

Hi Krzysztof,

On 07/14/2016 06:17 PM, Krzysztof Kozlowski wrote:
> Exynos5410 supports eMMC version 4.41 so HS200 is the top mode which
> should be configured.  This is reflected in usage of
> "samsung,exynos5250-dw-mshc" compatible.  However DTS contained also
> property "mmc-hs400-1_8v" which is parsed by MMC core therefore
> resulting in mixed configuration.  MMC core set HS400 but dwmmc_exynos
> driver did not configure the data strobe for HS400 DDR mode.
>
> Removal of HS400 properties fixes semi-random mmc errors during boot:
>    mmc_host mmc0: Bus speed (slot 0) = 400000000Hz (slot req 200000000Hz, actual 200000000HZ div = 1)
>    mmc0: mmc_select_hs400 failed, error -84
>    mmc0: error -84 whilst initialising MMC card
>
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> ---
>   arch/arm/boot/dts/exynos5410-odroidxu.dts | 2 --
>   1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm/boot/dts/exynos5410-odroidxu.dts b/arch/arm/boot/dts/exynos5410-odroidxu.dts
> index d9499310a301..7536164438ca 100644
> --- a/arch/arm/boot/dts/exynos5410-odroidxu.dts
> +++ b/arch/arm/boot/dts/exynos5410-odroidxu.dts
> @@ -447,14 +447,12 @@
>   	samsung,dw-mshc-ciu-div = <3>;
>   	samsung,dw-mshc-sdr-timing = <0 4>;
>   	samsung,dw-mshc-ddr-timing = <0 2>;
> -	samsung,dw-mshc-hs400-timing = <0 2>;
not sure but can we use /delete-property/ option for this removable?
>   	samsung,read-strobe-delay = <90>;
this also need to be removed.
>   	pinctrl-names = "default";
>   	pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus1 &sd0_bus4 &sd0_bus8 &sd0_cd>;
>   	bus-width = <8>;
>   	cap-mmc-highspeed;
>   	mmc-hs200-1_8v;
> -	mmc-hs400-1_8v;
same as above if possible use /delete-property/
>   	vmmc-supply = <&ldo20_reg>;
>   	vqmmc-supply = <&ldo11_reg>;
>   };