Re: ahci(4): Disable PMP for AMD AHCI controler

On Fri, Jul 24 2026, Jan Klemkow wrote:

> On Thu, Jul 23, 2026 at 08:52:21PM -0700, Mike Larkin wrote:
>> On Thu, Jul 23, 2026 at 08:50:09PM -0700, Mike Larkin wrote:
>> > On Tue, Jul 21, 2026 at 02:32:46PM +0200, Jan Klemkow wrote:
>> > > On Tue, Jul 21, 2026 at 05:02:04AM -0700, Mike Larkin wrote:
>> > > > On Tue, Jul 21, 2026 at 09:39:22AM +0200, Jan Klemkow wrote:
>> > > > > On Tue, Jul 21, 2026 at 09:55:50AM +1000, Jonathan Matthew wrote:
>> > > > > > On Mon, Jul 20, 2026 at 08:17:33PM +0200, Jan Klemkow wrote:
>> > > > > > > The AMD AHCI controller advertises port multiplier support but probing
>> > > > > > > for a PMP on each port costs 10 seconds of timeouts per disk at attach
>> > > > > > > time.  We should disable it, like we do it for Intel.
>> > > > > >
>> > > > > > What systems does this controller appear in?
>> > > > >
>> > > > > ASRock Rack TURIND8-2L2T mainboard with an AMD EPYC 9115 processor.
>> > > > > I'm not sure in which component contains the SATA controller.
>> > > > >
>> > > > > > Do you know if port multipliers actually work with it?
>> > > > >
>> > > > > No, I don't have hardware to test the SATA port multiplier function.
>> > > > > Do you know what I would need to test it?
>> > > > >
>> > > >
>> > > > I think I have one of these on my EPYC 7773X ASUS machine. Please hold off
>> > > > until I have a chance to test cos that's got all my storage attached to it :)
>> > >
>> > > Could you also check on your machine, if it hangs for 10s for every port
>> > > at this attach stage?
>> > >
>> > > ahci2 at pci15 dev 0 function 0 "AMD FCH AHCI" rev 0x93: msi, AHCI 1.3.1
>> > > ahci2: port 0: 6.0Gb/s
>> > > ahci2: port 1: 6.0Gb/s
>> > > ahci2: port 2: 6.0Gb/s
>> > > ahci2: port 3: 6.0Gb/s
>> >
>> > With this diff none of my ahci* attach.
>> >
>> > Without the diff, it does take 10s between attaches, but at least it works.
>> 
>> I guess technically I should say:
>> 
>> "no sd* on ahci* attaches"
>> 
>> The ahci does attach but it just immediately skips every sd(4) as if nothing is
>> present.
>
> Thanks for testing Mike!
>
> I thought the PMP feature were outdated and obsolete.  So, the right
> solution is to fix the PMP attachment algorithm.
>
> Which hardware do you use in this setup?  Which Mainboard and how are
> your disks being connected to you mainboard?  Do you have a special
> backplane for the disks in you case?  Or do you use a special sata
> controller?  Can you send me a dmesg of you storage system?
>
> Thanks,
> Jan

I'll hijack this a bit, I quickly tested this on my Lenovo E485 laptop
and seemed to hit same issue that sd* attached during boot. The boot
process stops to think at ahci step for a while so improvement to it
would be welcome.

Here's current dmesg from this laptop.

timo

OpenBSD 8.0-beta (GENERIC.MP) #48: Mon Jul 20 11:32:13 MDT 2026
    [email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 16733204480 (15958MB)
avail mem = 16202395648 (15451MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 3.1 @ 0x986eb000 (62 entries)
bios0: vendor LENOVO version "R0UET81W (1.61 )" date 03/17/2022
bios0: LENOVO 20KUCTO1WW
efi0 at bios0: UEFI 2.6
efi0: Lenovo rev 0x1610
acpi0 at bios0: ACPI 5.0
acpi0: sleep states S0 S3 S4 S5
acpi0: tables DSDT FACP SSDT SSDT CRAT CDIT SSDT TPM2 UEFI MSDM BATB HPET APIC MCFG SBST WSMT VFCT IVRS FPDT SSDT SSDT SSDT BGRT UEFI SSDT
acpi0: wakeup devices GPP0(S3) GPP1(S3) GPP2(S3) GPP3(S3) GPP4(S3) GPP5(S3) GPP6(S3) GP17(S3) XHC0(S3) XHC1(S3) GP18(S3) LID_(S3) SLPB(S3)
acpitimer0 at acpi0: 3579545 Hz, 32 bits
acpihpet0 at acpi0: 14318180 Hz
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.00 MHz, 17-11-00, patch 0810100b
cpu0: cpuid 1 edx=178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,HTT> ecx=76d8320b<SSE3,PCLMUL,MWAIT,SSSE3,FMA3,CX16,SSE4.1,SSE4.2,MOVBE,POPCNT,AES,XSAVE,AVX,F16C,RDRAND>
cpu0: cpuid 6 eax=4<ARAT> ecx=1<EFFFREQ>
cpu0: cpuid 7.0 ebx=209c01a9<FSGSBASE,BMI1,AVX2,SMEP,BMI2,RDSEED,ADX,SMAP,CLFLUSHOPT,SHA>
cpu0: cpuid d.1 eax=f<XSAVEOPT,XSAVEC,XGETBV1,XSAVES>
cpu0: cpuid 80000001 edx=2fd3fbff<NXE,MMXX,FFXSR,PAGE1GB,RDTSCP,LONG> ecx=35c233ff<LAHF,CMPLEG,SVM,EAPICSP,AMCR8,ABM,SSE4A,MASSE,3DNOWP,OSVW,SKINIT,TCE,TOPEXT,CPCTR,DBKP,PCTRL3,MWAITX>
cpu0: cpuid 80000007 edx=6599<HWPSTATE,ITSC>
cpu0: cpuid 80000008 ebx=1007<IBPB>
cpu0: cpuid 8000001F eax=f<SME,SEV,PFLUSH_MSR,SEVES> ecx=f
cpu0: 32KB 64b/line 8-way D-cache, 64KB 64b/line 4-way I-cache, 512KB 64b/line 8-way L2 cache, 4MB 64b/line 16-way L3 cache
cpu0: smt 0, core 0, package 0, type P
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 25MHz
cpu0: mwait min=64, max=64, C-substates=1.1, IBE
cpu1 at mainbus0: apid 1 (application processor)
cpu1: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.00 MHz, 17-11-00, patch 0810100b
cpu1: smt 1, core 0, package 0, type SP
tsc: cpu0/cpu1: sync test failed
timecounter: active counter changed: tsc -> acpihpet0
cpu2 at mainbus0: apid 2 (application processor)
cpu2: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.00 MHz, 17-11-00, patch 0810100b
cpu2: smt 0, core 1, package 0, type P
cpu3 at mainbus0: apid 3 (application processor)
cpu3: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.01 MHz, 17-11-00, patch 0810100b
cpu3: smt 1, core 1, package 0, type SP
cpu4 at mainbus0: apid 4 (application processor)
cpu4: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.00 MHz, 17-11-00, patch 0810100b
cpu4: smt 0, core 2, package 0, type P
cpu5 at mainbus0: apid 5 (application processor)
cpu5: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.01 MHz, 17-11-00, patch 0810100b
cpu5: smt 1, core 2, package 0, type SP
cpu6 at mainbus0: apid 6 (application processor)
cpu6: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.00 MHz, 17-11-00, patch 0810100b
cpu6: smt 0, core 3, package 0, type P
cpu7 at mainbus0: apid 7 (application processor)
cpu7: AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx, 2000.01 MHz, 17-11-00, patch 0810100b
cpu7: smt 1, core 3, package 0, type SP
ioapic0 at mainbus0: apid 32 pa 0xfec00000, version 21, 24 pins, can't remap
ioapic1 at mainbus0: apid 33 pa 0xfec01000, version 21, 32 pins, can't remap
acpimcfg0 at acpi0
acpimcfg0: addr 0xf8000000, bus 0-63
acpiprt0 at acpi0: bus 0 (PCI0)
acpiprt1 at acpi0: bus 1 (GPP0)
acpiprt2 at acpi0: bus 2 (GPP1)
acpiprt3 at acpi0: bus 3 (GPP2)
acpiprt4 at acpi0: bus -1 (GPP3)
acpiprt5 at acpi0: bus -1 (GPP4)
acpiprt6 at acpi0: bus 4 (GPP5)
acpiprt7 at acpi0: bus -1 (GPP6)
acpiprt8 at acpi0: bus 5 (GP17)
acpiprt9 at acpi0: bus 6 (GP18)
acpiec0 at acpi0
acpibtn0 at acpi0: PWRB
acpipci0 at acpi0 PCI0: 0x00000010 0x00000011 0x00000000
acpicmos0 at acpi0
acpibat0 at acpi0: BAT0 model "5810W138" serial 13057 type LION oem "SMP"
acpiac0 at acpi0: AC unit online
acpithinkpad0 at acpi0: version 2.0
"LEN0071" at acpi0 not configured
"LEN2060" at acpi0 not configured
"SMB0001" at acpi0 not configured
acpibtn1 at acpi0: LID_(wakeup)
acpibtn2 at acpi0: SLPB(wakeup)
"PNP0C14" at acpi0 not configured
"PNP0C14" at acpi0 not configured
"PNP0C14" at acpi0 not configured
tpm0 at acpi0 TPM_ 2.0 (TIS) addr 0xfed40000/0x5000, device 0x0000104a rev 0x4e
"USBC000" at acpi0 not configured
acpicpu0 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu1 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu2 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu3 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu4 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu5 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu6 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpicpu7 at acpi0: C2(0@400 io@0x414), C1(0@1 mwait), PSS
acpipwrres0 at acpi0: P0ST, resource for SATA
acpipwrres1 at acpi0: P3ST, resource for SATA
acpivideo0 at acpi0: VGA_
acpivout0 at acpivideo0: LCD_
cpu0: 2000 MHz: speeds: 2000 1700 1600 MHz
pci0 at mainbus0 bus 0
ksmn0 at pci0 dev 0 function 0 "AMD 17h/1xh Root Complex" rev 0x00
"AMD 17h/1xh IOMMU" rev 0x00 at pci0 dev 0 function 2 not configured
pchb0 at pci0 dev 1 function 0 "AMD 17h PCIE" rev 0x00
ppb0 at pci0 dev 1 function 1 "AMD 17h/1xh PCIE" rev 0x00: msi
pci1 at ppb0 bus 1
nvme0 at pci1 dev 0 function 0 "Lenovo NVMe" rev 0x00: msix, NVMe 1.2
nvme0: LENSE20256GMSP34MEAT2TA, firmware 2.6.8341, serial 1227066205564
scsibus1 at nvme0: 2 targets, initiator 0
sd0 at scsibus1 targ 1 lun 0: <NVMe, LENSE20256GMSP34, 2.6.>
sd0: 244198MB, 512 bytes/sector, 500118192 sectors
ppb1 at pci0 dev 1 function 2 "AMD 17h/1xh PCIE" rev 0x00: msi
pci2 at ppb1 bus 2
re0 at pci2 dev 0 function 0 "Realtek 8168" rev 0x10: RTL8168GU/8111GU (0x5080), msi, address e8:6a:64:33:83:cc
rgephy0 at re0 phy 7: RTL8251, rev. 0
ppb2 at pci0 dev 1 function 3 "AMD 17h/1xh PCIE" rev 0x00: msi
pci3 at ppb2 bus 3
sdhc0 at pci3 dev 0 function 0 "O2 Micro 0Z8621 SD/MMC" rev 0x01: msi
sdhc0: SDHC 4.00, 50 MHz base clock
sdmmc0 at sdhc0: 4-bit, sd high-speed, mmc high-speed, ddr52, dma
ppb3 at pci0 dev 1 function 6 "AMD 17h/1xh PCIE" rev 0x00: msi
pci4 at ppb3 bus 4
iwm0 at pci4 dev 0 function 0 "Intel Dual Band Wireless-AC 8265" rev 0x78, msi
pchb1 at pci0 dev 8 function 0 "AMD 17h PCIE" rev 0x00
ppb4 at pci0 dev 8 function 1 "AMD 17h/1xh PCIE" rev 0x00
pci5 at ppb4 bus 5
amdgpu0 at pci5 dev 0 function 0 "ATI Radeon Vega" rev 0xc4
drm0 at amdgpu0
amdgpu0: msi
azalia0 at pci5 dev 0 function 1 "ATI Radeon Vega HD Audio" rev 0x00: msi
azalia0: no supported codecs
ccp0 at pci5 dev 0 function 2 "AMD 17h/1xh Crypto" rev 0x00
xhci0 at pci5 dev 0 function 3 "AMD 17h/1xh xHCI" rev 0x00: msix, xHCI 1.10
usb0 at xhci0: USB revision 3.0
uhub0 at usb0 configuration 1 interface 0 "AMD xHCI root hub" rev 3.00/1.00 addr 1
xhci1 at pci5 dev 0 function 4 "AMD 17h/1xh xHCI" rev 0x00: msix, xHCI 1.10
usb1 at xhci1: USB revision 3.0
uhub1 at usb1 configuration 1 interface 0 "AMD xHCI root hub" rev 3.00/1.00 addr 1
azalia1 at pci5 dev 0 function 6 "AMD 17h/1xh HD Audio" rev 0x00: msi
azalia1: codecs: Conexant/0x5111
audio0 at azalia1
ppb5 at pci0 dev 8 function 2 "AMD 17h/1xh PCIE" rev 0x00
pci6 at ppb5 bus 6
ahci0 at pci6 dev 0 function 0 "AMD FCH AHCI" rev 0x61: msi, AHCI 1.3.1
ahci0: port 0: 6.0Gb/s
scsibus2 at ahci0: 32 targets
sd1 at scsibus2 targ 0 lun 0: <ATA, Samsung SSD 850, EXM0> naa.50025388400c34c6
sd1: 488386MB, 512 bytes/sector, 1000215216 sectors, thin
piixpm0 at pci0 dev 20 function 0 "AMD FCH SMBus" rev 0x61: SMI
iic0 at piixpm0
admtemp0 at iic0 addr 0x18: Xeon
admtemp1 at iic0 addr 0x1a: Xeon
spdmem0 at iic0 addr 0x50: 8GB DDR4 SDRAM PC4-19200 SO-DIMM with thermal sensor
spdmem1 at iic0 addr 0x52: 8GB DDR4 SDRAM PC4-19200 SO-DIMM with thermal sensor
iic1 at piixpm0
pcib0 at pci0 dev 20 function 3 "AMD FCH LPC" rev 0x51
pchb2 at pci0 dev 24 function 0 "AMD 17h/1xh Data Fabric" rev 0x00
pchb3 at pci0 dev 24 function 1 "AMD 17h/1xh Data Fabric" rev 0x00
pchb4 at pci0 dev 24 function 2 "AMD 17h/1xh Data Fabric" rev 0x00
pchb5 at pci0 dev 24 function 3 "AMD 17h/1xh Data Fabric" rev 0x00
pchb6 at pci0 dev 24 function 4 "AMD 17h/1xh Data Fabric" rev 0x00
pchb7 at pci0 dev 24 function 5 "AMD 17h/1xh Data Fabric" rev 0x00
pchb8 at pci0 dev 24 function 6 "AMD 17h/1xh Data Fabric" rev 0x00
pchb9 at pci0 dev 24 function 7 "AMD 17h/1xh Data Fabric" rev 0x00
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 8.16, 0x1e2b1 0x940300 0x373740 0xf016a3 0x12e800
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
vmm0 at mainbus0: SVM/RVI
efifb at mainbus0 not configured
iwm0: restrict all mbufs to low memory
vscsi0 at root
scsibus3 at vscsi0: 256 targets
softraid0 at root
scsibus4 at softraid0: 256 targets
sd2 at scsibus4 targ 1 lun 0: <OPENBSD, SR CRYPTO, 006>
sd2: 227678MB, 512 bytes/sector, 466284711 sectors
root on sd2a (88532b67c09ce3ee.a) swap on sd2b dump on sd2b
iwm0: hw rev 0x230, fw ver 36.ca7b901d.0, address 68:ec:c5:ad:9a:cb
amdgpu0: RAVEN GC 9.1.0 8 CU rev 0x01
amdgpu0: 1920x1080, 32bpp
wsdisplay0 at amdgpu0 mux 1: console (std, vt100 emulation), using wskbd0
wsdisplay0: screen 1-5 added (std, vt100 emulation)
uhidev0 at uhub0 port 2 configuration 1 interface 0 "Kensington Kensington Slimblade Trackball" rev 2.00/1.00 addr 2
uhidev0: iclass 3/1
ums0 at uhidev0: 4 buttons, Z dir
wsmouse2 at ums0 mux 0
uhub0: device problem, disabling port 1
uhub2 at uhub0 port 1 configuration 1 interface 0 "Texas Instruments product 0x8442" rev 2.10/1.00 addr 3
uhidev1 at uhub2 port 3 configuration 1 interface 0 "Keyboardio Atreus" rev 1.10/0.00 addr 4
uhidev1: iclass 3/1
ukbd0 at uhidev1: 8 variable keys, 6 key codes
wskbd1 at ukbd0 mux 1
wskbd1: connecting to wsdisplay0
uhidev2 at uhub2 port 3 configuration 1 interface 1 "Keyboardio Atreus" rev 1.10/0.00 addr 4
uhidev2: iclass 3/0, 5 report ids
ums1 at uhidev2 reportid 2: 5 buttons, Z and W dir
wsmouse3 at ums1 mux 0
uhid0 at uhidev2 reportid 3: input=2, output=0, feature=0
ucc0 at uhidev2 reportid 4: 672 usages, 20 keys, array
wskbd2 at ucc0 mux 1
wskbd2: connecting to wsdisplay0
ukbd1 at uhidev2 reportid 5: 128 variable keys, 0 key codes
wskbd3 at ukbd1 mux 1
wskbd3: connecting to wsdisplay0
uhidev3 at uhub2 port 3 configuration 1 interface 2 "Keyboardio Atreus" rev 1.10/0.00 addr 4
uhidev3: iclass 3/0
uhid1 at uhidev3: input=32, output=32, feature=0
uhidev4 at uhub2 port 5 configuration 1 interface 0 "Texas Instruments product 0x82ff" rev 2.01/2.00 addr 5
uhidev4: iclass 3/0
uhid2 at uhidev4: input=1027, output=1028, feature=2
uaudio0 at uhub2 port 4 configuration 1 interface 1 "HIFIMAN HIFIMAN-EF500" rev 2.00/2.01 addr 6
uaudio0: class v2, high-speed, async, channels: 2 play, 0 rec, 3 ctls
audio1 at uaudio0
uaudio0: sync play xfer, err = 6