On 10/11/2024 6:44 pm, Dragan Simic wrote:
The regulator-{min,max}-microvolt values for the vdd_gpu regulator in the
PinePhone Pro device dts file are too restrictive, which prevents the highest
GPU OPP from being used, slowing the GPU down unnecessarily. Let's fix that
by making the regulator-{min,max}-microvolt values less strict, using the
voltage range that the Silergy SYR838 chip used for the vdd_gpu regulator is
actually capable of producing. [1][2]
Specifying the absolute limits which the regulator driver necessarily
already knows doesn't seem particularly useful... Moreover, the RK3399
datasheet specifies the operating range for GPU_VDD as 0.80-1.20V, so at
the very least, allowing the regulator to go outside that range seems
inadvisable. However there's a separate datasheet for the RK3399-T
variant, which does specify this 875-975mV range and a maximum GPU clock
of 600MHz, along with the same 1.5GHz max. Cortex-A72 clock as
advertised for RK3399S, so it seems quite possible that these GPU
constraints here are in fact intentional as well. Obviously users are
free to overclock and overvolt if they wish - I do for my
actively-cooled RK3399 board :) - but it's a different matter for
mainline to force it upon them.
Thanks,
Robin.
This also eliminates the following error messages from the kernel log:
core: _opp_supported_by_regulators: OPP minuV: 1100000 maxuV: 1150000, not supported by regulator
panfrost ff9a0000.gpu: _opp_add: OPP not supported by regulators (800000000)
These changes to the regulator-{min,max}-microvolt values make the PinePhone
Pro device dts consistent with the dts files for other Rockchip RK3399-based
boards and devices. It's possible to be more strict here, by specifying the
regulator-{min,max}-microvolt values that don't go outside of what the GPU
actually may use, as the consumer of the vdd_gpu regulator, but those changes
are left for a later directory-wide regulator cleanup.
[1] https://files.pine64.org/doc/PinePhonePro/PinephonePro-Schematic-V1.0-20211127.pdf
[2] https://www.t-firefly.com/download/Firefly-RK3399/docs/Chip%20Specifications/DC-DC_SYR837_838.pdf
Fixes: 78a21c7d5952 ("arm64: dts: rockchip: Add initial support for Pine64 PinePhone Pro")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dragan Simic <dsimic@xxxxxxxxxxx>
---
arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
index 1a44582a49fb..956d64f5b271 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
@@ -410,8 +410,8 @@ vdd_gpu: regulator@41 {
pinctrl-names = "default";
pinctrl-0 = <&vsel2_pin>;
regulator-name = "vdd_gpu";
- regulator-min-microvolt = <875000>;
- regulator-max-microvolt = <975000>;
+ regulator-min-microvolt = <712500>;
+ regulator-max-microvolt = <1500000>;
regulator-ramp-delay = <1000>;
regulator-always-on;
regulator-boot-on;
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