Re: [PATCH 1/2] arm64: dts: rk3328: add gpu opp table

[Alex Bee]

Am 18.10.21 um 18:49 schrieb Nicolas Frattaroli:
> On Samstag, 16. Oktober 2021 17:45:44 CEST Trevor Woerner wrote:
> > Add an operating-points table and cooling entry to the GPU on the
> > RK3328 SoC to improve its performance. According to its datasheet[1]
> > the maximum frequency of the Mali-450 MP2 GPU found on the RK3328 SoC
> > is 500MHz.
> >
> > On my rock64 device, under x11, glmark2-es2 performance increased from
> > around 60 to just over 100. Same device running glmark2-es2 under
> > wayland/weston improved from just over 100 to just over 200.
> >
> > [1] https://rockchip.fr/RK3328%20datasheet%20V1.2.pdf
> >
> > Signed-off-by: Trevor Woerner <twoerner@xxxxxxxxx>
> > ---
> >   arch/arm64/boot/dts/rockchip/rk3328.dtsi | 26 +++++++++++++++++++++++-
> >   1 file changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3328.dtsi
> > b/arch/arm64/boot/dts/rockchip/rk3328.dtsi index 8c821acb21ff..5e1dcf71e414
> > 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3328.dtsi
> > +++ b/arch/arm64/boot/dts/rockchip/rk3328.dtsi
> > @@ -532,7 +532,8 @@ map0 {
> >   					cooling-device = <&cpu0
> THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >   							 <&cpu1
> THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >   							 <&cpu2
> THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> > -							 <&cpu3
> THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> > +							 <&cpu3
> THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> > +							 <&gpu
> THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> >   					contribution = <4096>;
> >   				};
> >   			};
> > @@ -617,6 +618,29 @@ gpu: gpu@ff300000 {
> >   		clocks = <&cru ACLK_GPU>, <&cru ACLK_GPU>;
> >   		clock-names = "bus", "core";
> >   		resets = <&cru SRST_GPU_A>;
> > +		operating-points-v2 = <&gpu_opp_table>;
> > +		#cooling-cells = <2>;
> > +	};
> > +
> > +	gpu_opp_table: gpu-opp-table {
> > +		compatible = "operating-points-v2";
> > +
> > +		opp-200000000 {
> > +			opp-hz = /bits/ 64 <200000000>;
> > +			opp-microvolt = <1100000>;
> > +		};
> > +		opp-300000000 {
> > +			opp-hz = /bits/ 64 <300000000>;
> > +			opp-microvolt = <1100000>;
> > +		};
> > +		opp-400000000 {
> > +			opp-hz = /bits/ 64 <400000000>;
> > +			opp-microvolt = <1100000>;
> > +		};
> > +		opp-500000000 {
> > +			opp-hz = /bits/ 64 <500000000>;
> > +			opp-microvolt = <1100000>;
> > +		};
> >   	};
> >
> >   	h265e_mmu: iommu@ff330200 {
>
> As for whether this works as described on a ROCK64 for glmark2-es2-wayland:

The probably most "convenient" and also future-proof solution upstream 
for that is to define voltage ranges á la



opp-200000000 {

		opp-hz = /bits/ 64 <200000000>;

		opp-microvolt = <950000 950000 1150000>;



};

and so on.

And then adapt the regulator-min-microvolt of the logic regulator like

vdd_logic: DCDC_REG1 {

	regulator-name = "vdd_logic";

	regulator-min-microvolt = <1050000>;

...
};

That way all opp-points will be taken, but its ensured, that vdd_log 
never goes below 1.05 V

> Tested-by: Nicolas Frattaroli <frattaroli.nicolas@xxxxxxxxx>
>
> There is some stuff worth noting that LibreELEC does on this SoC[1]:
>
> 1. they use 1.05V for all OPPs up to and including 400 MHz
> 2. they run 500 MHz at 1.15V instead (though 1.10V seemed to work for both of
> us)

That might be true for your boards, but note that the required voltage 
is per "leakage level" defined in efuse bits - something we do not 
support for Rockchip upstream currently - see [1]

> 3. they disable 500 MHz because 1.15V was apparently too high for rkvdec.
>
> 3 is currently not very relevant because mainline Linux has no rkvdec node in
> the rk3328 dtsi, and we're not running at 1.15V.
>
> I've decided to add their rkvdec dtsi patch[2] on top anyway, and saw no
> complaints from the rkvdec module while glmark2-es2-drm was running. However,
> it's not like I tried to actually hardware decode video while it was running
> because the userspace situation still won't let me without compiling entirely
> too much stuff from git. Though the rkvdec module was loaded and present.
You will see no complaints from the module , but you will see the SoC 
crashing if both is running at the same time - see rkvdec-opp-table 
downstream [2]

[1] 
https://github.com/rockchip-linux/kernel/blob/develop-4.4/arch/arm64/boot/dts/rockchip/rk3328.dtsi#L750-L751

[2] 
https://github.com/rockchip-linux/kernel/blob/develop-4.4/arch/arm64/boot/dts/rockchip/rk3328.dtsi#L840-L867

Alex

> [1]: https://github.com/LibreELEC/LibreELEC.tv/commit/
> 9a6be0d36ba7ff3c3d5df798682d47a1de594ac0
> [2]: https://github.com/LibreELEC/LibreELEC.tv/blob/master/projects/Rockchip/
> patches/linux/default/linux-1001-v4l2-rockchip.patch#L860-L935
>
>
>
>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-rockchip