Hi Jeffrey,

On Wed, 12 Dec 2018 at 18:23, J= effrey Hugo <j= hugo@codeaurora.org> wrote:

On 12/12/2018 10:13 AM, Loic Poulain wrote:
> In the same way as for msm8974-hammerhead, l21 load, used for SDCARD > VMMC, needs to be increased in order to prevent any voltage drop issue= s
> (due to limited current) happening with some SDCARDS or during specifi= c
> operations (e.g. write).
>
> Fixes: 660a9763c6a9 (arm64: dts: qcom: db820c: Add pm8994 regulator no= de)
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> ---
>=C2=A0 =C2=A0arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi | 2 ++
>=C2=A0 =C2=A01 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi b/arch/arm64= /boot/dts/qcom/apq8096-db820c.dtsi
> index 104cad9..c15e2c0 100644
> --- a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
> +++ b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
> @@ -634,6 +634,8 @@
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0l21 {
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0regula= tor-min-microvolt =3D <2950000>;
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0regula= tor-max-microvolt =3D <2950000>;
> +=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0regulator-al= low-set-load;
> +=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0regulator-sy= stem-load =3D <200000>;
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0};
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0l22 {
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0regula= tor-min-microvolt =3D <3300000>;
>

I'm curious, why not update sdhci-msm to set the load on the regulator?=

Yes you're right, and I saw that t= here is ongoing work:

https://patchwork.kernel.org/patch/10630731/

Howerver I thought this change would be a quicker fix and easi= er to backport in stable trees.

I assume all the device-tree vmmc= loads will be removed at some point when driven from sdhci.

Regards,

Loic

=C2=A0

--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.