This is current/amd64 on a Thinkpad X230i. It seems that the C3 cpu state is only supported when the machine boots on battery (full dmesgs below):
--- /tmp/dmesg.bat Sat Nov 9 11:55:55 2024 +++ /tmp/dmesg.ac Sat Nov 9 11:55:55 2024 -acpiac0 at acpi0: AC unit offline +acpiac0 at acpi0: AC unit online -acpicpu0 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS -acpicpu1 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS -acpicpu2 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS -acpicpu3 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS +acpicpu0 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS +acpicpu1 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS +acpicpu2 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS +acpicpu3 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS Is this intended? apmd is running with apmd_flags="-A -z 5 -t 60". Plugging and unplugging AC is logged as such, but no messages about (a change in supported) C states appear, such as in the booting dmesg . Jan dmesg when booting on battery: OpenBSD 7.6-current (GENERIC.MP) #417: Wed Nov 6 15:53:38 MST 2024 dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP real mem = 8234086400 (7852MB) avail mem = 7961251840 (7592MB) random: good seed from bootblocks mpath0 at root scsibus0 at mpath0: 256 targets mainbus0 at root bios0 at mainbus0: SMBIOS rev. 2.7 @ 0xdae9c000 (69 entries) bios0: vendor LENOVO version "G2ETB7WW (2.77 )" date 09/24/2019 bios0: LENOVO 2325T7Z acpi0 at bios0: ACPI 5.0 acpi0: sleep states S0 S3 S4 S5 acpi0: tables DSDT FACP SLIC TCPA SSDT SSDT SSDT HPET APIC MCFG ECDT FPDT ASF! UEFI UEFI POAT SSDT SSDT UEFI DBG2 acpi0: wakeup devices LID_(S4) SLPB(S3) IGBE(S4) EXP3(S4) XHCI(S3) EHC1(S3) EHC2(S3) HDEF(S4) acpitimer0 at acpi0: 3579545 Hz, 24 bits acpihpet0 at acpi0: 14318179 Hz acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat cpu0 at mainbus0: apid 0 (boot processor) cpu0: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 1197.34 MHz, 06-3a-09, patch 00000021 cpu0: cpuid 1 edx=bfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> ecx=35bae3bf<SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,XSAVE,AVX,F16C> cpu0: cpuid 6 eax=75<SENSOR,ARAT> ecx=9<EFFFREQ> cpu0: cpuid 7.0 ebx=281<FSGSBASE,SMEP,ERMS> edx=9c000400<MD_CLEAR,IBRS,IBPB,STIBP,L1DF,SSBD> cpu0: cpuid a vers=3, gp=4, gpwidth=48, ff=3, ffwidth=48 cpu0: cpuid d.1 eax=1<XSAVEOPT> cpu0: cpuid 80000001 edx=28100800<NXE,RDTSCP,LONG> ecx=1<LAHF> cpu0: cpuid 80000007 edx=100<ITSC> cpu0: MELTDOWN cpu0: 32KB 64b/line 8-way D-cache, 32KB 64b/line 8-way I-cache, 256KB 64b/line 8-way L2 cache, 3MB 64b/line 12-way L3 cache cpu0: smt 0, core 0, package 0 mtrr: Pentium Pro MTRR support, 10 var ranges, 88 fixed ranges cpu0: apic clock running at 99MHz cpu0: mwait min=64, max=64, C-substates=0.2.1.1.2, IBE cpu1 at mainbus0: apid 1 (application processor) cpu1: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 1197.30 MHz, 06-3a-09, patch 00000021 cpu1: smt 1, core 0, package 0 cpu2 at mainbus0: apid 2 (application processor) cpu2: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 1197.31 MHz, 06-3a-09, patch 00000021 cpu2: smt 0, core 1, package 0 cpu3 at mainbus0: apid 3 (application processor) cpu3: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 1197.30 MHz, 06-3a-09, patch 00000021 cpu3: smt 1, core 1, package 0 ioapic0 at mainbus0: apid 2 pa 0xfec00000, version 20, 24 pins acpimcfg0 at acpi0 acpimcfg0: addr 0xf8000000, bus 0-63 acpiec0 at acpi0 acpiprt0 at acpi0: bus 0 (PCI0) acpiprt1 at acpi0: bus -1 (PEG_) acpiprt2 at acpi0: bus 2 (EXP1) acpiprt3 at acpi0: bus 3 (EXP2) acpiprt4 at acpi0: bus 4 (EXP3) acpibtn0 at acpi0: LID_(wakeup) acpibtn1 at acpi0: SLPB(wakeup) acpipci0 at acpi0 PCI0: 0x00000000 0x00000011 0x00000001 acpicmos0 at acpi0 acpibat0 at acpi0: BAT0 model "45N1025" serial 1094 type LION oem "LGC" acpiac0 at acpi0: AC unit offline "LEN0078" at acpi0 not configured acpithinkpad0 at acpi0: version 1.0 "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured acpicpu0 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS acpicpu1 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS acpicpu2 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS acpicpu3 at acpi0: C3(200@87 mwait.1@0x30), C2(500@59 mwait.1@0x10), C1(1000@1 mwait.1), PSS acpipwrres0 at acpi0: PUBS, resource for XHCI, EHC1, EHC2 acpitz0 at acpi0: critical temperature is 103 degC acpidock0 at acpi0: GDCK not docked (0) acpivideo0 at acpi0: VID_ acpivout0 at acpivideo0: LCD0 acpivideo1 at acpi0: VID_ cpu0: using VERW MDS workaround (except on vmm entry) cpu0: Enhanced SpeedStep 1197 MHz: speeds: 2400, 2300, 2200, 2100, 2000, 1900, 1800, 1700, 1600, 1500, 1400, 1300, 1200 MHz pci0 at mainbus0 bus 0 pchb0 at pci0 dev 0 function 0 "Intel Core 3G Host" rev 0x09 inteldrm0 at pci0 dev 2 function 0 "Intel HD Graphics 4000" rev 0x09 drm0 at inteldrm0 inteldrm0: msi, IVYBRIDGE, gen 7 xhci0 at pci0 dev 20 function 0 "Intel 7 Series xHCI" rev 0x04: msi, xHCI 1.0 usb0 at xhci0: USB revision 3.0 uhub0 at usb0 configuration 1 interface 0 "Intel xHCI root hub" rev 3.00/1.00 addr 1 "Intel 7 Series MEI" rev 0x04 at pci0 dev 22 function 0 not configured em0 at pci0 dev 25 function 0 "Intel 82579LM" rev 0x04: msi, address 3c:97:0e:63:a5:25 ehci0 at pci0 dev 26 function 0 "Intel 7 Series USB" rev 0x04: apic 2 int 16 usb1 at ehci0: USB revision 2.0 uhub1 at usb1 configuration 1 interface 0 "Intel EHCI root hub" rev 2.00/1.00 addr 1 azalia0 at pci0 dev 27 function 0 "Intel 7 Series HD Audio" rev 0x04: msi azalia0: codecs: Realtek ALC269, Intel/0x2806, using Realtek ALC269 audio0 at azalia0 ppb0 at pci0 dev 28 function 0 "Intel 7 Series PCIE" rev 0xc4: msi pci1 at ppb0 bus 2 sdhc0 at pci1 dev 0 function 0 "Ricoh 5U823 SD/MMC" rev 0x04: apic 2 int 16 sdhc0: SDHC 3.00, 50 MHz base clock sdmmc0 at sdhc0: 4-bit, sd high-speed, mmc high-speed, dma ppb1 at pci0 dev 28 function 1 "Intel 7 Series PCIE" rev 0xc4: msi pci2 at ppb1 bus 3 iwn0 at pci2 dev 0 function 0 "Intel Centrino Advanced-N 6205" rev 0x34: msi, MIMO 2T2R, MoW, address e0:9d:31:9b:37:64 ppb2 at pci0 dev 28 function 2 "Intel 7 Series PCIE" rev 0xc4: msi pci3 at ppb2 bus 4 ehci1 at pci0 dev 29 function 0 "Intel 7 Series USB" rev 0x04: apic 2 int 23 usb2 at ehci1: USB revision 2.0 uhub2 at usb2 configuration 1 interface 0 "Intel EHCI root hub" rev 2.00/1.00 addr 1 pcib0 at pci0 dev 31 function 0 "Intel QM77 LPC" rev 0x04 ahci0 at pci0 dev 31 function 2 "Intel 7 Series AHCI" rev 0x04: msi, AHCI 1.3 ahci0: port 0: 6.0Gb/s scsibus1 at ahci0: 32 targets sd0 at scsibus1 targ 0 lun 0: <ATA, KingDian S180 60, F.00> naa.5000000000000000 sd0: 57241MB, 512 bytes/sector, 117231408 sectors, thin ichiic0 at pci0 dev 31 function 3 "Intel 7 Series SMBus" rev 0x04: apic 2 int 18 iic0 at ichiic0 spdmem0 at iic0 addr 0x50: 4GB DDR3 SDRAM PC3-12800 SO-DIMM spdmem1 at iic0 addr 0x51: 4GB DDR3 SDRAM PC3-12800 SO-DIMM isa0 at pcib0 isadma0 at isa0 pckbc0 at isa0 port 0x60/5 irq 1 irq 12 pckbd0 at pckbc0 (kbd slot) wskbd0 at pckbd0: console keyboard pms0 at pckbc0 (aux slot) wsmouse0 at pms0 mux 0 wsmouse1 at pms0 mux 0 pms0: Synaptics clickpad, firmware 8.1, 0x1e2b1 0x940300 0x194b40 0xd002a3 0x123800 pcppi0 at isa0 port 0x61 spkr0 at pcppi0 vmm0 at mainbus0: VMX/EPT uhub3 at uhub1 port 1 configuration 1 interface 0 "Intel Rate Matching Hub" rev 2.00/0.00 addr 2 ugen0 at uhub3 port 3 "Auth Biometric Coprocessor" rev 1.10/0.01 addr 3 ugen1 at uhub3 port 4 "Broadcom Corp BCM20702A0" rev 2.00/1.12 addr 4 uhub4 at uhub2 port 1 configuration 1 interface 0 "Intel Rate Matching Hub" rev 2.00/0.00 addr 2 vscsi0 at root scsibus2 at vscsi0: 256 targets softraid0 at root scsibus3 at softraid0: 256 targets root on sd0a (1bb9b839fb175dff.a) swap on sd0b dump on sd0b inteldrm0: 1366x768, 32bpp wsdisplay0 at inteldrm0 mux 1: console (std, vt100 emulation), using wskbd0 wsdisplay0: screen 1-5 added (std, vt100 emulation) dmesg when booting on AC: OpenBSD 7.6-current (GENERIC.MP) #417: Wed Nov 6 15:53:38 MST 2024 dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP real mem = 8234086400 (7852MB) avail mem = 7961251840 (7592MB) random: good seed from bootblocks mpath0 at root scsibus0 at mpath0: 256 targets mainbus0 at root bios0 at mainbus0: SMBIOS rev. 2.7 @ 0xdae9c000 (69 entries) bios0: vendor LENOVO version "G2ETB7WW (2.77 )" date 09/24/2019 bios0: LENOVO 2325T7Z acpi0 at bios0: ACPI 5.0 acpi0: sleep states S0 S3 S4 S5 acpi0: tables DSDT FACP SLIC TCPA SSDT SSDT SSDT HPET APIC MCFG ECDT FPDT ASF! UEFI UEFI POAT SSDT SSDT UEFI DBG2 acpi0: wakeup devices LID_(S4) SLPB(S3) IGBE(S4) EXP3(S4) XHCI(S3) EHC1(S3) EHC2(S3) HDEF(S4) acpitimer0 at acpi0: 3579545 Hz, 24 bits acpihpet0 at acpi0: 14318179 Hz acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat cpu0 at mainbus0: apid 0 (boot processor) cpu0: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 2394.68 MHz, 06-3a-09, patch 00000021 cpu0: cpuid 1 edx=bfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> ecx=35bae3bf<SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,XSAVE,AVX,F16C> cpu0: cpuid 6 eax=75<SENSOR,ARAT> ecx=9<EFFFREQ> cpu0: cpuid 7.0 ebx=281<FSGSBASE,SMEP,ERMS> edx=9c000400<MD_CLEAR,IBRS,IBPB,STIBP,L1DF,SSBD> cpu0: cpuid a vers=3, gp=4, gpwidth=48, ff=3, ffwidth=48 cpu0: cpuid d.1 eax=1<XSAVEOPT> cpu0: cpuid 80000001 edx=28100800<NXE,RDTSCP,LONG> ecx=1<LAHF> cpu0: cpuid 80000007 edx=100<ITSC> cpu0: MELTDOWN cpu0: 32KB 64b/line 8-way D-cache, 32KB 64b/line 8-way I-cache, 256KB 64b/line 8-way L2 cache, 3MB 64b/line 12-way L3 cache cpu0: smt 0, core 0, package 0 mtrr: Pentium Pro MTRR support, 10 var ranges, 88 fixed ranges cpu0: apic clock running at 99MHz cpu0: mwait min=64, max=64, C-substates=0.2.1.1.2, IBE cpu1 at mainbus0: apid 1 (application processor) cpu1: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 2394.60 MHz, 06-3a-09, patch 00000021 cpu1: smt 1, core 0, package 0 cpu2 at mainbus0: apid 2 (application processor) cpu2: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 2394.59 MHz, 06-3a-09, patch 00000021 cpu2: smt 0, core 1, package 0 cpu3 at mainbus0: apid 3 (application processor) cpu3: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz, 2394.66 MHz, 06-3a-09, patch 00000021 cpu3: smt 1, core 1, package 0 ioapic0 at mainbus0: apid 2 pa 0xfec00000, version 20, 24 pins acpimcfg0 at acpi0 acpimcfg0: addr 0xf8000000, bus 0-63 acpiec0 at acpi0 acpiprt0 at acpi0: bus 0 (PCI0) acpiprt1 at acpi0: bus -1 (PEG_) acpiprt2 at acpi0: bus 2 (EXP1) acpiprt3 at acpi0: bus 3 (EXP2) acpiprt4 at acpi0: bus 4 (EXP3) acpibtn0 at acpi0: LID_(wakeup) acpibtn1 at acpi0: SLPB(wakeup) acpipci0 at acpi0 PCI0: 0x00000000 0x00000011 0x00000001 acpicmos0 at acpi0 acpibat0 at acpi0: BAT0 model "45N1025" serial 1094 type LION oem "LGC" acpiac0 at acpi0: AC unit online "LEN0078" at acpi0 not configured acpithinkpad0 at acpi0: version 1.0 "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured acpicpu0 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS acpicpu1 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS acpicpu2 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS acpicpu3 at acpi0: C2(350@80 mwait.1@0x20), C1(1000@1 mwait.1), PSS acpipwrres0 at acpi0: PUBS, resource for XHCI, EHC1, EHC2 acpitz0 at acpi0: critical temperature is 103 degC acpidock0 at acpi0: GDCK not docked (0) acpivideo0 at acpi0: VID_ acpivout0 at acpivideo0: LCD0 acpivideo1 at acpi0: VID_ cpu0: using VERW MDS workaround (except on vmm entry) cpu0: Enhanced SpeedStep 2394 MHz: speeds: 2400, 2300, 2200, 2100, 2000, 1900, 1800, 1700, 1600, 1500, 1400, 1300, 1200 MHz pci0 at mainbus0 bus 0 pchb0 at pci0 dev 0 function 0 "Intel Core 3G Host" rev 0x09 inteldrm0 at pci0 dev 2 function 0 "Intel HD Graphics 4000" rev 0x09 drm0 at inteldrm0 inteldrm0: msi, IVYBRIDGE, gen 7 xhci0 at pci0 dev 20 function 0 "Intel 7 Series xHCI" rev 0x04: msi, xHCI 1.0 usb0 at xhci0: USB revision 3.0 uhub0 at usb0 configuration 1 interface 0 "Intel xHCI root hub" rev 3.00/1.00 addr 1 "Intel 7 Series MEI" rev 0x04 at pci0 dev 22 function 0 not configured em0 at pci0 dev 25 function 0 "Intel 82579LM" rev 0x04: msi, address 3c:97:0e:63:a5:25 ehci0 at pci0 dev 26 function 0 "Intel 7 Series USB" rev 0x04: apic 2 int 16 usb1 at ehci0: USB revision 2.0 uhub1 at usb1 configuration 1 interface 0 "Intel EHCI root hub" rev 2.00/1.00 addr 1 azalia0 at pci0 dev 27 function 0 "Intel 7 Series HD Audio" rev 0x04: msi azalia0: codecs: Realtek ALC269, Intel/0x2806, using Realtek ALC269 audio0 at azalia0 ppb0 at pci0 dev 28 function 0 "Intel 7 Series PCIE" rev 0xc4: msi pci1 at ppb0 bus 2 sdhc0 at pci1 dev 0 function 0 "Ricoh 5U822 SD/MMC" rev 0x07: apic 2 int 16 sdhc0: SDHC 3.00, 50 MHz base clock sdmmc0 at sdhc0: 4-bit, sd high-speed, mmc high-speed, dma ppb1 at pci0 dev 28 function 1 "Intel 7 Series PCIE" rev 0xc4: msi pci2 at ppb1 bus 3 iwn0 at pci2 dev 0 function 0 "Intel Centrino Advanced-N 6205" rev 0x34: msi, MIMO 2T2R, MoW, address e0:9d:31:9b:37:64 ppb2 at pci0 dev 28 function 2 "Intel 7 Series PCIE" rev 0xc4: msi pci3 at ppb2 bus 4 ehci1 at pci0 dev 29 function 0 "Intel 7 Series USB" rev 0x04: apic 2 int 23 usb2 at ehci1: USB revision 2.0 uhub2 at usb2 configuration 1 interface 0 "Intel EHCI root hub" rev 2.00/1.00 addr 1 pcib0 at pci0 dev 31 function 0 "Intel QM77 LPC" rev 0x04 ahci0 at pci0 dev 31 function 2 "Intel 7 Series AHCI" rev 0x04: msi, AHCI 1.3 ahci0: port 0: 6.0Gb/s scsibus1 at ahci0: 32 targets sd0 at scsibus1 targ 0 lun 0: <ATA, KingDian S180 60, F.00> naa.5000000000000000 sd0: 57241MB, 512 bytes/sector, 117231408 sectors, thin ichiic0 at pci0 dev 31 function 3 "Intel 7 Series SMBus" rev 0x04: apic 2 int 18 iic0 at ichiic0 spdmem0 at iic0 addr 0x50: 4GB DDR3 SDRAM PC3-12800 SO-DIMM spdmem1 at iic0 addr 0x51: 4GB DDR3 SDRAM PC3-12800 SO-DIMM isa0 at pcib0 isadma0 at isa0 pckbc0 at isa0 port 0x60/5 irq 1 irq 12 pckbd0 at pckbc0 (kbd slot) wskbd0 at pckbd0: console keyboard pms0 at pckbc0 (aux slot) wsmouse0 at pms0 mux 0 wsmouse1 at pms0 mux 0 pms0: Synaptics clickpad, firmware 8.1, 0x1e2b1 0x940300 0x194b40 0xd002a3 0x123800 pcppi0 at isa0 port 0x61 spkr0 at pcppi0 vmm0 at mainbus0: VMX/EPT uhub3 at uhub1 port 1 configuration 1 interface 0 "Intel Rate Matching Hub" rev 2.00/0.00 addr 2 ugen0 at uhub3 port 3 "Auth Biometric Coprocessor" rev 1.10/0.01 addr 3 ugen1 at uhub3 port 4 "Broadcom Corp BCM20702A0" rev 2.00/1.12 addr 4 uhub4 at uhub2 port 1 configuration 1 interface 0 "Intel Rate Matching Hub" rev 2.00/0.00 addr 2 vscsi0 at root scsibus2 at vscsi0: 256 targets softraid0 at root scsibus3 at softraid0: 256 targets root on sd0a (1bb9b839fb175dff.a) swap on sd0b dump on sd0b inteldrm0: 1366x768, 32bpp wsdisplay0 at inteldrm0 mux 1: console (std, vt100 emulation), using wskbd0 wsdisplay0: screen 1-5 added (std, vt100 emulation)