Re: [PATCH v2 2/2] riscv: dts: spacemit: Add cpu scaling for K1 SoC

Anand Moon
2026-04-16T11:37:51Z

Hi Shuwei,

Thanks for sharing the details.

On Thu, 16 Apr 2026 at 11:29, Shuwei Wu <shuwei.wu@mailbox.org> wrote:
>
> On Tue Apr 14, 2026 at 9:25 PM CST, Anand Moon wrote:
> > Hi Shuwei,
> >
> > On Fri, 10 Apr 2026 at 13:30, Shuwei Wu <shuwei.wu@mailbox.org> wrote:
> >>
> >> Add Operating Performance Points (OPP) tables and CPU clock properties
> >> for the two clusters in the SpacemiT K1 SoC.
> >>
> >> Also assign the CPU power supply (cpu-supply) for the Banana Pi BPI-F3
> >> board to fully enable CPU DVFS.
> >>
> >> Signed-off-by: Shuwei Wu <shuwei.wu@mailbox.org>
> >>
> >> ---
> >> Changes in v2:
> >> - Add k1-opp.dtsi with OPP tables for both CPU clusters
> >> - Assign CPU supplies and include OPP table for Banana Pi BPI-F3
> >> ---
> >> arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 35 +++++++-
> >> arch/riscv/boot/dts/spacemit/k1-opp.dtsi | 105 ++++++++++++++++++++++++
> >> arch/riscv/boot/dts/spacemit/k1.dtsi | 8 ++
> >> 3 files changed, 147 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> >> index 444c3b1e6f44..3780593f610d 100644
> >> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> >> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> >> @@ -5,6 +5,7 @@
> >>
> >> #include "k1.dtsi"
> >> #include "k1-pinctrl.dtsi"
> >> +#include "k1-opp.dtsi"
> >>
> >> / {
> >> model = "Banana Pi BPI-F3";
> >> @@ -86,6 +87,38 @@ &combo_phy {
> >> status = "okay";
> >> };
> >>
> >> +&cpu_0 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_1 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_2 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_3 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_4 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_5 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_6 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> +&cpu_7 {
> >> + cpu-supply = <&buck1_3v45>;
> >> +};
> >> +
> >> &emmc {
> >> bus-width = <8>;
> >> mmc-hs400-1_8v;
> >> @@ -201,7 +234,7 @@ pmic@41 {
> >> dldoin2-supply = <&buck5>;
> >>
> >> regulators {
> >> - buck1 {
> >> + buck1_3v45: buck1 {
> >> regulator-min-microvolt = <500000>;
> >> regulator-max-microvolt = <3450000>;
> >> regulator-ramp-delay = <5000>;
> >> diff --git a/arch/riscv/boot/dts/spacemit/k1-opp.dtsi b/arch/riscv/boot/dts/spacemit/k1-opp.dtsi
> >> new file mode 100644
> >> index 000000000000..768ae390686d
> >> --- /dev/null
> >> +++ b/arch/riscv/boot/dts/spacemit/k1-opp.dtsi
> >> @@ -0,0 +1,105 @@
> >> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> >> +
> >> +/ {
> >> + cluster0_opp_table: opp-table-cluster0 {
> >> + compatible = "operating-points-v2";
> >> + opp-shared;
> >> +
> >> + opp-614400000 {
> >> + opp-hz = /bits/ 64 <614400000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-819000000 {
> >> + opp-hz = /bits/ 64 <819000000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-1000000000 {
> >> + opp-hz = /bits/ 64 <1000000000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-1228800000 {
> >> + opp-hz = /bits/ 64 <1228800000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-1600000000 {
> >> + opp-hz = /bits/ 64 <1600000000>;
> >> + opp-microvolt = <1050000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> + };
> >> +
> >> + cluster1_opp_table: opp-table-cluster1 {
> >> + compatible = "operating-points-v2";
> >> + opp-shared;
> >> +
> >> + opp-614400000 {
> >> + opp-hz = /bits/ 64 <614400000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-819000000 {
> >> + opp-hz = /bits/ 64 <819000000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-1000000000 {
> >> + opp-hz = /bits/ 64 <1000000000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-1228800000 {
> >> + opp-hz = /bits/ 64 <1228800000>;
> >> + opp-microvolt = <950000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> +
> >> + opp-1600000000 {
> >> + opp-hz = /bits/ 64 <1600000000>;
> >> + opp-microvolt = <1050000>;
> >> + clock-latency-ns = <200000>;
> >> + };
> >> + };
> >> +};
> >> +
> >> +&cpu_0 {
> >> + operating-points-v2 = <&cluster0_opp_table>;
> >> +};
> >> +
> >> +&cpu_1 {
> >> + operating-points-v2 = <&cluster0_opp_table>;
> >> +};
> >> +
> >> +&cpu_2 {
> >> + operating-points-v2 = <&cluster0_opp_table>;
> >> +};
> >> +
> >> +&cpu_3 {
> >> + operating-points-v2 = <&cluster0_opp_table>;
> >> +};
> >> +
> >> +&cpu_4 {
> >> + operating-points-v2 = <&cluster1_opp_table>;
> >> +};
> >> +
> >> +&cpu_5 {
> >> + operating-points-v2 = <&cluster1_opp_table>;
> >> +};
> >> +
> >> +&cpu_6 {
> >> + operating-points-v2 = <&cluster1_opp_table>;
> >> +};
> >> +
> >> +&cpu_7 {
> >> + operating-points-v2 = <&cluster1_opp_table>;
> >> +};
> >> diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
> >> index 529ec68e9c23..bdd109b81730 100644
> >> --- a/arch/riscv/boot/dts/spacemit/k1.dtsi
> >> +++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
> >> @@ -54,6 +54,7 @@ cpu_0: cpu@0 {
> >> compatible = "spacemit,x60", "riscv";
> >> device_type = "cpu";
> >> reg = <0>;
> >> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> >> riscv,isa = "rv64imafdcbv_zicbom_zicbop_zicboz_zicntr_zicond_zicsr_zifencei_zihintpause_zihpm_zfh_zba_zbb_zbc_zbs_zkt_zvfh_zvkt_sscofpmf_sstc_svinval_svnapot_svpbmt";
> >> riscv,isa-base = "rv64i";
> >> riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "b", "v", "zicbom",
> >> @@ -84,6 +85,7 @@ cpu_1: cpu@1 {
> >> compatible = "spacemit,x60", "riscv";
> >> device_type = "cpu";
> >> reg = <1>;
> >> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> >
> > Based on the Spacemit kernel source, the k1-x_opp_table.dtsi file
> > defines several additional clocks for the Operating Performance Points
> > (OPP) table:
> >
> > clocks = <&ccu CLK_CPU_C0_ACE>, <&ccu CLK_CPU_C1_ACE>, <&ccu CLK_CPU_C0_TCM>,
> > <&ccu CLK_CCI550>, <&ccu CLK_PLL3>, <&ccu
> > CLK_CPU_C0_HI>, <&ccu CLK_CPU_C1_HI>;
> > clock-names = "ace0","ace1","tcm","cci","pll3", "c0hi", "c1hi";
> >
> > These hardware clocks are also explicitly registered in the APMU clock driver
> > via the k1_ccu_apmu_hws array, confirming their availability for frequency
> > and voltage scaling on the K1-X SoC.
> >
> > static struct clk_hw *k1_ccu_apmu_hws[] = {
> > [CLK_CCI550] = &cci550_clk.common.hw,
> > [CLK_CPU_C0_HI] = &cpu_c0_hi_clk.common.hw,
> > [CLK_CPU_C0_CORE] = &cpu_c0_core_clk.common.hw,
> > [CLK_CPU_C0_ACE] = &cpu_c0_ace_clk.common.hw,
> > [CLK_CPU_C0_TCM] = &cpu_c0_tcm_clk.common.hw,
> > [CLK_CPU_C1_HI] = &cpu_c1_hi_clk.common.hw,
> > [CLK_CPU_C1_CORE] = &cpu_c1_core_clk.common.hw,
> > [CLK_CPU_C1_ACE] = &cpu_c1_ace_clk.common.hw,
> >
> > Yes, it is possible to add these clocks for DVFS to work correctly,
> > provided they are managed by the appropriate driver and declared in
> > the Device Tree (DT).
> >
> > Thanks
> > -Anand
>
> Thanks for your review and for pointing this out.
>
> Regarding the clocks you mentioned, I'd like to clarify their roles based on
> the K1 datasheet. Taking Cluster 0 as an example, c0_core_clk is the primary
> clock for the cluster. c0_ace_clk and c0_tcm_clk are children derived from it,
> defaulting to half the frequency of their parent core clock, while c0_hi_clk
> represents the high-speed path selection.
> Cluster 1 follows the same structure.
>
> Based on the official SpacemiT Bianbu OS source, the spacemit-cpufreq.c driver
> mainly performs the following tasks:
> 1. Sets the CCI550 clock frequency to 614MHz.
> 2. Sets the clock frequencies of c0_ace_clk, c1_ace1_clk, and c0_tcm_clk to half
> the frequency of their parent clock.
> 3. For the 1.6GHz OPP, it sets the PLL3 frequency to 3.2GHz and the
> c0_hi_clk/c1_hi_clk frequencies to 1.6GHz.
>
> I booted with the manufacturer's OpenWRT image and used debugfs to confirm that
> the clock states are exactly as described above.
>
> At 1.6GHz:
> Clock Source & Tree Rate (Hz) HW Enable Consumer
> ---------------------------------------------------------------------------
> pll3 3,200,000,000 Y deviceless
> └─ pll3_d2 1,600,000,000 Y deviceless
> ├─ cpu_c1_hi_clk 1,600,000,000 Y deviceless
> │ └─ cpu_c1_pclk 1,600,000,000 Y cpu0
> │ └─ cpu_c1_ace_clk 800,000,000 Y deviceless
> └─ cpu_c0_hi_clk 1,600,000,000 Y deviceless
> └─ cpu_c0_core_clk 1,600,000,000 Y cpu0
> ├─ cpu_c0_tcm_clk 800,000,000 Y deviceless
> └─ cpu_c0_ace_clk 800,000,000 Y deviceless
>
> pll1_2457p6_vco 2,457,600,000 Y deviceless
> └─ pll1_d4 614,400,000 Y deviceless
> └─ pll1_d4_614p4 614,400,000 Y deviceless
> └─ cci550_clk 614,400,000 Y deviceless
>
> At 1.228GHz:
> Clock Source & Tree Rate (Hz) HW Enable Consumer
> ---------------------------------------------------------------------------
> pll1_2457p6_vco 2,457,600,000 Y deviceless
> └─ pll1_d2 1,228,800,000 Y deviceless
> └─ pll1_d2_1228p8 1,228,800,000 Y deviceless
> ├─ cpu_c0_core_clk 1,228,800,000 Y cpu0
> │ ├─ cpu_c0_tcm_clk 614,400,000 Y deviceless
> │ └─ cpu_c0_ace_clk 614,400,000 Y deviceless
> └─ cpu_c1_pclk 1,228,800,000 Y cpu0
> └─ cpu_c1_ace_clk 614,400,000 Y deviceless
> └─ pll1_d4 614,400,000 Y deviceless
> └─ pll1_d4_614p4 614,400,000 Y deviceless
> └─ cci550_clk 614,400,000 Y deviceless
>
> pll3 3,200,000,000 Y deviceless
> └─ pll3_d2 1,600,000,000 Y deviceless
> ├─ cpu_c1_hi_clk 1,600,000,000 Y deviceless
> └─ cpu_c0_hi_clk 1,600,000,000 Y deviceless
> └─ pll3_d3 1,066,666,666 Y deviceless
>
> Regarding the necessity of listing these clocks in the DT, my analysis is as follows:
> 1. For CCI550, I did not find a clear definition of this clock's specific role
> in the SoC datasheet. Although the vendor kernel increases its frequency,
> my benchmarks show that maintaining the mainline default (245.76MHz) has a
> negligible impact on CPU performance.
> 2. For ACE and TCM clocks, they function as synchronous children of the core
> clock with a default divide-by-2 ratio. Since they scale automatically relative
> to c0_core_clk/c1_core_clk and no other peripherals depend on them, they do not
> require manual management in the OPP table.
> 3. For the high-speed path, the underlying clock controller logic already handles
> the parent MUX switching and PLL3 scaling automatically when clk_set_rate()
> is called on the core clock.
>
> I have verified this by checking the hardware state in the mainline kernel.
> The clock tree matches the vendor kernel's configuration:
>
> At 1.6GHz:
> Clock Source & Tree Rate (Hz) HW Enable Consumer
> ---------------------------------------------------------------------------
> pll3 3,200,000,000 Y deviceless
> └─ pll3_d2 1,600,000,000 Y deviceless
> ├─ cpu_c1_hi_clk 1,600,000,000 Y deviceless
> │ └─ cpu_c1_core_clk 1,600,000,000 Y cpu4
> │ └─ cpu_c1_ace_clk 800,000,000 Y deviceless
> └─ cpu_c0_hi_clk 1,600,000,000 Y deviceless
> └─ cpu_c0_core_clk 1,600,000,000 Y cpu0
> ├─ cpu_c0_tcm_clk 800,000,000 Y deviceless
> └─ cpu_c0_ace_clk 800,000,000 Y deviceless
>
> pll1 2,457,600,000 Y deviceless
> └─ pll1_d5 491,520,000 Y deviceless
> └─ pll1_d5_491p52 491,520,000 Y deviceless
> └─ cci550_clk 245,760,000 Y deviceless
>
> At 1.228GHz:
> Clock Source & Tree Rate (Hz) HW Enable Consumer
> ---------------------------------------------------------------------------
> pll1 2,457,600,000 Y deviceless
> ├─ pll1_d5 491,520,000 Y deviceless
> │ └─ pll1_d5_491p52 491,520,000 Y deviceless
> │ └─ cci550_clk 245,760,000 Y deviceless
> └─ pll1_d2 1,228,800,000 Y deviceless
> └─ pll1_d2_1228p8 1,228,800,000 Y deviceless
> └─ cpu_c0_core_clk 1,228,800,000 Y cpu0
> ├─ cpu_c0_tcm_clk 614,400,000 Y deviceless
> └─ cpu_c0_ace_clk 614,400,000 Y deviceless
>
> pll3 3,200,000,000 Y deviceless
> └─ pll3_d2 1,600,000,000 Y deviceless
> └─ cpu_c1_hi_clk 1,600,000,000 Y deviceless
> └─ cpu_c1_core_clk 1,600,000,000 Y cpu4
> └─ cpu_c1_ace_clk 800,000,000 Y deviceless
>

Thanks, I have verified the clocks are set to Y in
/sys/kernel/debug/clk/clk_summary

> Performance benchmarks also confirm that the current configuration is sufficient:
> Benchmark (AWK computation): time awk 'BEGIN{for(i=0;i<10000000;i++) sum+=i}'
> ----------------------------------------------------------------------------
> Frequency | Mainline Linux (s) | OpenWrt (s)
> (kHz) | Real (Total) | User (CPU) | Real (Total) | User (CPU) )
> -------------+---------------+---------------+---------------+--------------
> 1,600,000 | 1.82s | 1.81s | 1.73s | 1.73s
> 1,228,800 | 2.34s | 2.33s | 2.26s | 2.26s
> 1,000,000 | 2.94s | 2.86s | 2.78s | 2.78s
> 819,000 | 3.54s | 3.53s | 3.39s | 3.39s
> 614,400 | 4.73s | 4.71s | 4.51s | 4.51s
> ----------------------------------------------------------------------------
>
> In summary, because the clock controller correctly handles the internal dividers
> and parent switching, declaring only the primary core clock for each CPU node is
> sufficient for functional DVFS.
>
I have just tested this patch against next-20260415
But, I have observed this log on the Banana Pi F3 dev board with the
Banana PI - R4 heat sink and fan.

[ 5.803445][ T1] In-situ OAM (IOAM) with IPv6
[ 5.809605][ T1] NET: Registered PF_PACKET protocol family
[ 5.819098][ T1] Key type dns_resolver registered
[ 5.853430][ C2] cpu2: scalar unaligned word access speed is
1.60x byte access speed (fast)
[ 5.853431][ C3] cpu3: scalar unaligned word access speed is
1.67x byte access speed (fast)
[ 5.853440][ C7] cpu7: scalar unaligned word access speed is
8.10x byte access speed (fast)
[ 5.853432][ C1] cpu1: scalar unaligned word access speed is
3.98x byte access speed (fast)
[ 5.853431][ T1] cpu0: scalar unaligned word access speed is
2.33x byte access speed (fast)
[ 5.853436][ C5] cpu5: scalar unaligned word access speed is
2.29x byte access speed (fast)
[ 5.853436][ C6] cpu6: scalar unaligned word access speed is
2.58x byte access speed (fast)
[ 5.853431][ C4] cpu4: scalar unaligned word access speed is
2.07x byte access speed (fast)
[ 5.936544][ T92] mmcblk0boot0: mmc0:0001 AJTD4R 4.00 MiB
[ 6.003120][ T92] mmcblk0boot1: mmc0:0001 AJTD4R 4.00 MiB
[ 6.070909][ T92] mmcblk0rpmb: mmc0:0001 AJTD4R 4.00 MiB, chardev (244:0)
[ 6.380324][ T1] registered taskstats version 1
[ 6.407337][ T1] Loading compiled-in X.509 certificates
[ 6.594206][ T1] Loaded X.509 cert 'Build time autogenerated
kernel key: 19b81ec48e45e6ee983623417bad5096df8bbcf1'
[ 7.600343][ T1] Demotion targets for Node 0: null
[ 7.608583][ T1] kmemleak: Kernel memory leak detector
initialized (mem pool available: 1309)
[ 7.608646][ T120] kmemleak: Automatic memory scanning thread started
[ 7.624663][ T1] debug_vm_pgtable: [debug_vm_pgtable ]:
Validating architecture page table helpers
[ 7.636721][ T1] page_owner is disabled
[ 8.213648][ T74] debugfs: ':soc:gpio@d4019000-1' already exists
in 'domains'
[ 8.233502][ T74] debugfs: ':soc:gpio@d4019000-1' already exists
in 'domains'
[ 8.254012][ T74] debugfs: ':soc:gpio@d4019000-1' already exists
in 'domains'
[ 8.319431][ T74] printk: legacy console [ttyS0] disabled
[ 8.345811][ T74] d4017000.serial: ttyS0 at MMIO 0xd4017000 (irq
= 16, base_baud = 921600) is a XScale
[ 8.357331][ T74] printk: legacy console [ttyS0] enabled
[ 8.357331][ T74] printk: legacy console [ttyS0] enabled
[ 8.369971][ T74] printk: legacy bootconsole [uart0] disabled
[ 8.369971][ T74] printk: legacy bootconsole [uart0] disabled
[ 8.427040][ T74] /soc/i2c@d401d800/pmic@41: Fixed dependency
cycle(s) with /soc/i2c@d401d800/pmic@41/regulators/buck5
[ 8.634595][ T74] spacemit-p1-rtc spacemit-p1-rtc.1.auto:
registered as rtc0
[ 8.642732][ T74] spacemit-p1-rtc spacemit-p1-rtc.1.auto: setting
system clock to 2026-04-10T00:03:42 UTC (1775779422)
[ 8.766081][ T74] sdhci-spacemit d4280000.mmc: Got CD GPIO
[ 8.801855][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 8.806411][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 8.813413][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 8.818261][ T130] cpu cpu4: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 8.818307][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 8.827239][ T129] cpu cpu0: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 8.833161][ T130] cpu cpu4: Failed to set regulator voltages: -22
[ 8.842546][ T129] cpu cpu0: Failed to set regulator voltages: -22
[ 8.848941][ T130] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 8.855273][ T129] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 8.893720][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 8.904437][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 8.908515][ T129] cpu cpu0: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 8.918057][ T129] cpu cpu0: Failed to set regulator voltages: -22
[ 8.924402][ T129] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 8.945668][ T74] mmc1: SDHCI controller on d4280000.mmc
[d4280000.mmc] using ADMA
[ 8.976207][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 8.980156][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 8.986169][ T130] cpu cpu4: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 8.995473][ T130] cpu cpu4: Failed to set regulator voltages: -22
[ 9.001603][ T130] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 9.020028][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 9.024051][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 9.030122][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 9.036004][ T130] cpu cpu4: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 9.036059][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 9.045003][ T130] cpu cpu4: Failed to set regulator voltages: -22
[ 9.045077][ T130] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 9.058079][ T57] spacemit-k1-pcie ca800000.pcie: host bridge
/soc/pcie-bus/pcie@ca800000 ranges:
[ 9.064716][ T129] cpu cpu0: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 9.064745][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 9.064825][ T129] cpu cpu0: Failed to set regulator voltages: -22
[ 9.064889][ T129] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 9.065762][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 9.069924][ T60] spacemit-k1-pcie ca400000.pcie: host bridge
/soc/pcie-bus/pcie@ca400000 ranges:
[ 9.071122][ T60] spacemit-k1-pcie ca400000.pcie: IO
0x009f002000..0x009f101fff -> 0x0000000000
[ 9.073304][ T60] spacemit-k1-pcie ca400000.pcie: MEM
0x0090000000..0x009effffff -> 0x0090000000
[ 9.081407][ T74] at24 2-0050: 256 byte 24c02 EEPROM, read-only
[ 9.083047][ T130] cpu cpu4: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 9.083509][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 9.083614][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 9.083686][ T129] cpu cpu0: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 9.083845][ T129] cpu cpu0: Failed to set regulator voltages: -22
[ 9.083885][ T129] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 9.089945][ T57] spacemit-k1-pcie ca800000.pcie: IO
0x00b7002000..0x00b7101fff -> 0x0000000000
[ 9.092728][ T1] clk: Disabling unused clocks
[ 9.095269][ T130] cpu cpu4: Failed to set regulator voltages: -22
[ 9.096981][ T1] PM: genpd: Disabling unused power domains
[ 9.104949][ T57] spacemit-k1-pcie ca800000.pcie: MEM
0x00a0000000..0x00afffffff -> 0x00a0000000
[ 9.107986][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 9.108166][ T129] buck1: Restricting voltage, 1050000-950000uV
[ 9.108246][ T129] cpu cpu0: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 9.108311][ T129] cpu cpu0: Failed to set regulator voltages: -22
[ 9.108356][ T129] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 9.108582][ T130] cpufreq: __target_index: Failed to change cpu
frequency: -22
[ 9.113366][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 9.118144][ T57] spacemit-k1-pcie ca800000.pcie: MEM
0x00b0000000..0x00b6ffffff -> 0x00b0000000
[ 9.130386][ T130] buck1: Restricting voltage, 1050000-950000uV
[ 9.196246][ T130] cpu cpu4: _set_opp_voltage: failed to set
voltage (1050000 1050000 1050000 mV): -22
[ 9.202562][ T60] spacemit-k1-pcie ca400000.pcie: iATU: unroll T,
8 ob, 8 ib, align 4K, limit 4G
[ 9.206998][ T130] cpu cpu4: Failed to set regulator voltages: -22
[ 9.257180][ T130] cpufreq: __target_index: Failed to change cpu
frequency: -22

After reviewing the Banana Pi F3 schematics, I confirmed that Buck1 and Buck2
Both supply the CORE_0V9 with 0.9V±1% rail. To resolve the restriction errors,
I expanded the voltage range in the DTS to 500,000–950,000 µV.

Additionally, I updated the DTS to map the second CPU cluster (cores 4–7)
to Buck2 to better align with the hardware's power distribution.

[1] https://drive.google.com/file/d/19iLJ5xnCB_oK8VeQjkPGjzAn39WYyylv/view
(page 4)

Can you share your thoughts on the changes below?
$ git diff
diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index 7e300cca50d8..be53645ba0c6 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -102,19 +102,19 @@ &cpu_3 {
};

&cpu_4 {
- cpu-supply = <&buck1_3v45>;
+ cpu-supply = <&buck2_3v45>;
};

&cpu_5 {
- cpu-supply = <&buck1_3v45>;
+ cpu-supply = <&buck2_3v45>;
};

&cpu_6 {
- cpu-supply = <&buck1_3v45>;
+ cpu-supply = <&buck2_3v45>;
};

&cpu_7 {
- cpu-supply = <&buck1_3v45>;
+ cpu-supply = <&buck2_3v45>;
};

&emmc {
@@ -234,14 +234,14 @@ pmic@41 {
regulators {
buck1_3v45: buck1 {
regulator-min-microvolt = <500000>;
- regulator-max-microvolt = <3450000>;
+ regulator-max-microvolt = <950000>;
regulator-ramp-delay = <5000>;
regulator-always-on;
};

- buck2 {
+ buck2_3v45: buck2 {
regulator-min-microvolt = <500000>;
- regulator-max-microvolt = <3450000>;
+ regulator-max-microvolt = <950000>;
regulator-ramp-delay = <5000>;
regulator-always-on;
};
> --
> Best regards,
> Shuwei Wu

Thanks
-Anand