From: "Guilherme G. Piccoli" <gpiccoli@igalia.com> To: linux-arm-msm@vger.kernel.org Cc: agross@kernel.org, bjorn.andersson@linaro.org, gpiccoli@igalia.com, kernel@gpiccoli.net Subject: [PATCH] arm64: dts: qcom: db820c: Improve regulator voltage range and mark it as always-on Date: Mon, 27 Sep 2021 13:37:45 -0300 [thread overview] Message-ID: <20210927163745.2066610-1-gpiccoli@igalia.com> (raw) Commit 2317b87a2a6f ("arm64: dts: qcom: db820c: Add vdd_gfx and tie it into mmcc") introduced this voltage regulator which seems to be essential for the GPU, according to the board schematics [0]. The problem is that such commit sets the regulator min/max voltage range to a static value, which is a bit lower than the range supported to such regulator [1]. With that, the GPU is not stable as per my experiments (in a Dragonboard 820c-based board) - I've observed sudden reboots into a FW bad state. More than that, my experiment showed that this regulator must be set to always-on - this idea came from a commit in Linaro's tree, from Rajendra [2]. With the voltage range updated plus set as always-on, the GPU is working correctly, in a stable fashion. [0] See page 9 (VDD_GFX), at https://www.96boards.org/documentation/consumer/dragonboard/dragonboard820c/hardware-docs/files/db820c-schematics.pdf [1] See section 3.5.3 (FT-SMPS) in the "PMI8994/PMI8996 Power Management IC", at https://developer.qualcomm.com/download/sd820e/pmi8994pmi8996-power-management-ic-device-specification.pdf [2] https://git.linaro.org/landing-teams/working/qualcomm/kernel.git/commit/?h=release/qcomlt-4.14&id=75fb43f3a62 Cc: Rajendra Nayak <rnayak@codeaurora.org> Cc: Vinod Koul <vkoul@kernel.org> Fixes: 2317b87a2a6f ("arm64: dts: qcom: db820c: Add vdd_gfx and tie it into mmcc") Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> --- Hi Andy/Bjorn/all, this patch was tested in 5.14, but I've tested it in the linux-next tree as well and was able to apply there cleanly. I'm new in the DTS world, so my apologies in advance for any rookie mistake - suggestions are appreciated! Thanks in advance for the review, Guilherme arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi index 51e17094d7b1..977842068619 100644 --- a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi +++ b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi @@ -699,8 +699,11 @@ &pmi8994_spmi_regulators { vdd_gfx: s2@1700 { reg = <0x1700 0x100>; regulator-name = "VDD_GFX"; - regulator-min-microvolt = <980000>; - regulator-max-microvolt = <980000>; + regulator-min-microvolt = <350000>; + regulator-max-microvolt = <1350000>; + regulator-always-on; + status = "okay"; + }; }; -- 2.33.0
next reply other threads:[~2021-09-27 17:05 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-27 16:37 Guilherme G. Piccoli [this message] 2021-09-27 16:39 ` Guilherme G. Piccoli 2021-09-28 3:01 ` Bjorn Andersson 2021-09-28 21:54 ` Guilherme G. Piccoli 2021-09-28 22:55 ` Bjorn Andersson
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