From: Bjorn Andersson <andersson@kernel.org>
To: Arpit Saini <arpit.saini@oss.qualcomm.com>
Cc: Konrad Dybcio <konradybcio@kernel.org>,
Abel Vesa <abelvesa@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Neil Armstrong <neil.armstrong@linaro.org>,
Linus Walleij <linusw@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, mahadevan.p@oss.qualcomm.com,
rajeevny@qti.qualcomm.com,
Ayushi Makhija <ayushi.makhija@oss.qualcomm.com>,
Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Subject: Re: [PATCH v3] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801
Date: Sat, 7 Nov 2026 16:10:51 -0600 [thread overview]
Message-ID: <au-hKTUxMOPr4wvW@zenbook> (raw)
In-Reply-To: <20261007-resend-upstream-attention-v3-1-c2af21b3def4@oss.qualcomm.com>
On Wed, Oct 07, 2026 at 03:17:31PM +0530, Arpit Saini wrote:
> From: Ayushi Makhija <ayushi.makhija@oss.qualcomm.com>
>
> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
>
> Fixes: 4fca6849864d ("drm/panel: Add Novatek NT37801 panel driver")
> Signed-off-by: Ayushi Makhija <ayushi.makhija@oss.qualcomm.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Arpit Saini <arpit.saini@oss.qualcomm.com>
> ---
> Changes in v3:
> - Added my signed-off by.
> - Link to v2: https://lore.kernel.org/r/4f8a2731-4ea4-49d9-924c-ebde9fc58170@oss.qualcomm.com
> ---
> arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> index 64bc1cec612e..9ecb40e7e39f 100644
> --- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> +++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> @@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 {
>
> vreg_l12b_1p8: ldo12 {
> regulator-name = "vreg_l12b_1p8";
> - regulator-min-microvolt = <1200000>;
> + regulator-min-microvolt = <1650000>;
The power grid clearly states that L12B is expected to be at 1.8V.
So, while 1.65V is within range for the NT37801, it's not what the
hardware folks has told us to use.
Please review all the regulators and ensure they have ranges matching
the expectations from the power grid documentation.
Regards,
Bjorn
> regulator-max-microvolt = <1800000>;
> regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
> regulator-allow-set-load;
>
> ---
> base-commit: eea3fef32a9cf36abcb5975a5a594e4135a6b026
> change-id: 20261007-resend-upstream-attention-f964719a0733
>
> Best regards,
> --
> Arpit Saini <arpit.saini@oss.qualcomm.com>
>
prev parent reply other threads:[~2026-11-07 22:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-07 9:47 Arpit Saini
2026-11-07 22:10 ` Bjorn Andersson [this message]
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