On Wed, 20 Feb 2019 at 12:19, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote:
>
> The maximum voltage value for BUCK8 regulator on Odroid XU3/4 boards is
> set too low. Increase it to the 2000mV as specified on the board schematic.
> So far the board worked fine, because of the bug in the PMIC driver, which
> used incorrect step value for that regulator. It interpreted the voltage
> value set by the bootloader as 1500mV and kept it unchanged. The regulator
... as 1225mV (below the maximum voltage constraints) and kept it unchanged...
And we need cc-stable because previous value was clearly wrong (max
1.5 V while regulator is named 1.8 V) and the s2mps11 commit might end
up in stable kernels:
Fixes: 86a2d2ac5e5d ("ARM: dts: Add dts file for Odroid XU3 board")
Cc: <stable@xxxxxxxxxxxxxxx>
I can add these during applying.
BR,
Krzysztof
> driver has been however fixed recently in the commit 56b5d4ea778c
> ("regulator: s2mps11: Fix steps for buck7, buck8 and LDO35"), what results
> in reading the proper BUCK8 value and forcing it to 1500mV on boot. This
> is not enough for proper board operation and results in eMMC errors during
> heavy IO traffic. Increasing maximum voltage value for BUCK8 restores
> original driver behavior and fixes eMMC issues.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> arch/arm/boot/dts/exynos5422-odroid-core.dtsi | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
> index bf09eab90f8a..6bf3661293ee 100644
> --- a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
> +++ b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
> @@ -468,7 +468,7 @@
> buck8_reg: BUCK8 {
> regulator-name = "vdd_1.8v_ldo";
> regulator-min-microvolt = <800000>;
> - regulator-max-microvolt = <1500000>;
> + regulator-max-microvolt = <2000000>;
> regulator-always-on;
> regulator-boot-on;
> };
> --
> 2.17.1
>
