Re: ACPI Error: AE_AML_LOOP_TIMEOUT in \_SB.PCI0.SBUS.RDWD & \_SB.PCI0.SBRG.ADP1._PSR

[Armin Wolf]

Am 24.03.25 um 07:06 schrieb Naveen Kumar P:

> On Mon, Mar 24, 2025 at 3:25 AM Armin Wolf <W_Armin@xxxxxx> wrote:
> > Am 22.03.25 um 16:40 schrieb Naveen Kumar P:
> >
> > > On Sat, Mar 22, 2025 at 3:02 AM Armin Wolf <W_Armin@xxxxxx> wrote:
> > > > Am 19.03.25 um 12:29 schrieb Naveen Kumar P:
> > > >
> > > > > Hi all,
> > > > >
> > > > > I am encountering repeated AE_AML_LOOP_TIMEOUT errors in the ACPI RDWD
> > > > > & \_SB.PCI0.SBRG.ADP1._PSR methods. Below are relevant log entries
> > > > > from my system running Linux kernel 6.13.0+:
> > > > >
> > > > > [77998.038653]
> > > > >                   Initialized Local Variables for Method [RDWD]:
> > > > > [77998.038691]   Local1: 00000000d0fe9fee <Obj>           Integer
> > > > > 0000000000000015
> > > > > [77998.038862]   Local6: 00000000f41c1645 <Obj>           Integer
> > > > > 0000000000000000
> > > > > [77998.039031]   Local7: 0000000040665c5c <Obj>           Integer
> > > > > 000000000000AA55
> > > > >
> > > > > [77998.039237] Initialized Arguments for Method [RDWD]:  (2 arguments
> > > > > defined for method invocation)
> > > > > [77998.039273]   Arg0:   00000000397dc53d <Obj>           Integer
> > > > > 0000000000000014
> > > > > [77998.039442]   Arg1:   000000001099e334 <Obj>           Integer
> > > > > 0000000000000002
> > > > >
> > > > > [77998.039673] ACPI Error: Aborting method \_SB.PCI0.SBUS.RDWD due to
> > > > > previous error (AE_AML_LOOP_TIMEOUT) (20240827/psparse-529)
> > > > > [77998.040455] ACPI Error: Aborting method \_SB.PCI0.SBRG.ADP1._PSR
> > > > > due to previous error (AE_AML_LOOP_TIMEOUT) (20240827/psparse-529)
> > > > > [77998.043659] ACPI: \_SB_.PCI0.SBRG.ADP1: Error reading AC Adapter
> > > > > state: AE_AML_LOOP_TIMEOUT
> > > > >
> > > > > [78028.442980]
> > > > >                   Initialized Local Variables for Method [RDWD]:
> > > > > [78028.443019]   Local1: 00000000898a9a7e <Obj>           Integer
> > > > > 0000000000000017
> > > > > [78028.443192]   Local6: 000000000cf0c853 <Obj>           Integer
> > > > > 0000000000000000
> > > > > [78028.443362]   Local7: 00000000bb4aa65f <Obj>           Integer
> > > > > 000000000000AA55
> > > > >
> > > > > [78028.443569] Initialized Arguments for Method [RDWD]:  (2 arguments
> > > > > defined for method invocation)
> > > > > [78028.443606]   Arg0:   00000000ef8d445b <Obj>           Integer
> > > > > 0000000000000016
> > > > > [78028.443775]   Arg1:   000000006cacc887 <Obj>           Integer
> > > > > 0000000000000003
> > > > >
> > > > > [78028.444006] ACPI Error: Aborting method \_SB.PCI0.SBUS.RDWD due to
> > > > > previous error (AE_AML_LOOP_TIMEOUT) (20240827/psparse-529)
> > > > > [78028.446366] ACPI Error: Aborting method \_SB.PCI0.SBRG.ADP1._PSR
> > > > > due to previous error (AE_AML_LOOP_TIMEOUT) (20240827/psparse-529)
> > > > > [78028.451179] ACPI: \_SB_.PCI0.SBRG.ADP1: Error reading AC Adapter
> > > > > state: AE_AML_LOOP_TIMEOUT
> > > > >
> > > > > [78032.877472]
> > > > >                   Initialized Local Variables for Method [RDWD]:
> > > > > [78032.877509]   Local1: 00000000cf6291ae <Obj>           Integer
> > > > > 0000000000000017
> > > > > [78032.877682]   Local6: 0000000026aa8a7a <Obj>           Integer
> > > > > 0000000000000003
> > > > > [78032.877851]   Local7: 00000000acfa20e0 <Obj>           Integer
> > > > > 000000000000AA55
> > > > >
> > > > > [78032.878058] Initialized Arguments for Method [RDWD]:  (2 arguments
> > > > > defined for method invocation)
> > > > > [78032.878094]   Arg0:   00000000a186096f <Obj>           Integer
> > > > > 0000000000000016
> > > > > [78032.878262]   Arg1:   00000000d0e1eefe <Obj>           Integer
> > > > > 0000000000000003
> > > > >
> > > > > [78032.878492] ACPI Error: Aborting method \_SB.PCI0.SBUS.RDWD due to
> > > > > previous error (AE_AML_LOOP_TIMEOUT) (20240827/psparse-529)
> > > > > [78032.881011] ACPI Error: Aborting method \_SB.PCI0.SBRG.ADP1._PSR
> > > > > due to previous error (AE_AML_LOOP_TIMEOUT) (20240827/psparse-529)
> > > > > [78032.883061] ACPI: \_SB_.PCI0.SBRG.ADP1: Error reading AC Adapter
> > > > > state: AE_AML_LOOP_TIMEOUT
> > > > >
> > > > >
> > > > > This issue appears randomly, affecting the RDWD method, which is
> > > > > likely responsible for reading data from a bus, and consequently
> > > > > causing the _PSR method (power state read) to fail.
> > > > >
> > > > >
> > > > > Questions:
> > > > > 1. What typically causes AE_AML_LOOP_TIMEOUT errors?
> > > > AFAIK this error is caused by a while loop taking too long to finish. I suspect that
> > > > the ACPI bytecode tries to wait for a non-responsive hardware device.
> > > >
> > > > > 2. Could these ACPI errors impact PCI device access?
> > > > > Since the error originates from _SB.PCI0.SBUS.RDWD, could this failure
> > > > > affect PCI device communication or cause failures when accessing PCI
> > > > > devices?
> > > > I do not think so, the SBUS device is likely just a SMBus controller attached to the PCI bus.
> > > >
> > > > > 3. Could this be a firmware/BIOS issue?If so, what tools or steps
> > > > > should I use to verify and debug the ACPI tables?
> > > > It is either a hardware issue or a BIOS bug. Can you share the output of the "acpidump" utility
> > > > provided by the ACPICA project? Many Linux distributions already package ACPICA in their package repositories.
> > > I have attached the acpi.tar.gz file as requested. This archive
> > > contains the output from the "acpidump" utility. Below is a list of
> > > the files included in the archive:
> > >
> > > ls -ltr acpi
> > > total 760
> > > -rw-rw-r-- 1 murphy murphy 205609 Mar 19 18:30 acpi_tables.txt
> > > -rw-r--r-- 1 root   root       60 Mar 19 18:31 mcfg.dat
> > > -rw-r--r-- 1 root   root      132 Mar 19 18:31 apic.dat
> > > -rw-r--r-- 1 root   root      656 Mar 19 18:31 ssdt2.dat
> > > -rw-r--r-- 1 root   root       66 Mar 19 18:31 uefi.dat
> > > -rw-r--r-- 1 root   root    36402 Mar 19 18:31 dsdt.dat
> > > -rw-r--r-- 1 root   root      260 Mar 19 18:31 lpit.dat
> > > -rw-r--r-- 1 root   root      378 Mar 19 18:31 ssdt3.dat
> > > -rw-r--r-- 1 root   root      268 Mar 19 18:31 facp.dat
> > > -rw-r--r-- 1 root   root       68 Mar 19 18:31 fpdt.dat
> > > -rw-r--r-- 1 root   root     1891 Mar 19 18:31 ssdt1.dat
> > > -rw-r--r-- 1 root   root      332 Mar 19 18:31 csrt.dat
> > > -rw-r--r-- 1 root   root       56 Mar 19 18:31 hpet.dat
> > > -rw-r--r-- 1 root   root       64 Mar 19 18:31 facs.dat
> > > -rw-r--r-- 1 root   root      890 Mar 19 18:31 ssdt4.dat
> > > -rw-r--r-- 1 root   root      141 Mar 19 18:31 ssdt7.dat
> > > -rw-r--r-- 1 root   root     1075 Mar 19 18:31 ssdt5.dat
> > > -rw-r--r-- 1 root   root      351 Mar 19 18:31 ssdt6.dat
> > > -rw-rw-r-- 1 murphy murphy   5919 Mar 19 18:31 apic.dsl
> > > -rw-rw-r-- 1 murphy murphy   8131 Mar 19 18:31 csrt.dsl
> > > -rw-rw-r-- 1 murphy murphy 337832 Mar 19 18:31 dsdt.dsl
> > > -rw-rw-r-- 1 murphy murphy  10103 Mar 19 18:31 facp.dsl
> > > -rw-rw-r-- 1 murphy murphy   1368 Mar 19 18:31 facs.dsl
> > > -rw-rw-r-- 1 murphy murphy   1802 Mar 19 18:31 fpdt.dsl
> > > -rw-rw-r-- 1 murphy murphy   1863 Mar 19 18:31 hpet.dsl
> > > -rw-rw-r-- 1 murphy murphy   7523 Mar 19 18:31 lpit.dsl
> > > -rw-rw-r-- 1 murphy murphy   1524 Mar 19 18:31 mcfg.dsl
> > > -rw-rw-r-- 1 murphy murphy   9996 Mar 19 18:31 ssdt1.dsl
> > > -rw-rw-r-- 1 murphy murphy   7692 Mar 19 18:31 ssdt2.dsl
> > > -rw-rw-r-- 1 murphy murphy   4296 Mar 19 18:31 ssdt3.dsl
> > > -rw-rw-r-- 1 murphy murphy   8290 Mar 19 18:31 ssdt4.dsl
> > > -rw-rw-r-- 1 murphy murphy  16968 Mar 19 18:31 ssdt5.dsl
> > > -rw-rw-r-- 1 murphy murphy   2843 Mar 19 18:31 ssdt6.dsl
> > > -rw-rw-r-- 1 murphy murphy   1337 Mar 19 18:31 ssdt7.dsl
> > > -rw-rw-r-- 1 murphy murphy   1383 Mar 19 18:31 uefi.dsl
> > >
> > >
> > > Please let me know if you need any further details or additional
> > > information to assist in debugging the ACPI tables.
> > >
> > > Thank you for your help.
> > Alright, it seems that the ACPI bytecode is trying to access the charger using the smbus interface.
> > For some reason this takes over 30 seconds which causes the ACPI interpreter to throw this error.
> >
> > Can you check how long it normally takes to read the "online" sysfs attribute of the charger located
> > under "/sys/class/power_supply/ADP1"?
> I have written a script to measure the time it takes to read the
> "online" sysfs attribute of the charger located under
> /sys/class/power_supply/ADP1. Below is the script and the results:
>
> $cat test.sh
> #!/bin/bash
>
> start_time=$(date +%s%N)
> cat /sys/class/power_supply/ADP1/online
> end_time=$(date +%s%N)
>
> elapsed_time=$((end_time - start_time))
> echo "Time taken: $((elapsed_time / 1000000)) ms"
>
> $ sudo ./test.sh
> 1
> Time taken: 3809 ms
>
> $ sudo ./test.sh
> 1
> Time taken: 1688 ms
>
> $ sudo ./test.sh
> 1
> Time taken: 1685 ms
>
> $ sudo ./test.sh
> 1
> Time taken: 1688 ms
>
>
> As you can see, the first run took 3809 ms, and the subsequent runs
> took around 1688 ms.

That is suspiciously long for a smbus transaction, something is not right.

> > Also please share the output of "lspci -v".
> $ sudo lspci -v
> 00:00.0 Host bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series SoC Transaction Register (rev 11)
>          Subsystem: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series SoC Transaction Register
>          Flags: bus master, fast devsel, latency 0
>          Kernel driver in use: iosf_mbi_pci
>
> 00:02.0 VGA compatible controller: Intel Corporation Atom Processor
> Z36xxx/Z37xxx Series Graphics & Display (rev 11) (prog-if 00 [VGA
> controller])
>          DeviceName:  Onboard IGD
>          Subsystem: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series Graphics & Display
>          Flags: bus master, fast devsel, latency 0, IRQ 97
>          Memory at b0000000 (32-bit, non-prefetchable) [size=4M]
>          Memory at a0000000 (32-bit, prefetchable) [size=256M]
>          I/O ports at e080 [size=8]
>          Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
>          Capabilities: [d0] Power Management version 2
>          Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
>          Capabilities: [b0] Vendor Specific Information: Len=07 <?>
>          Kernel driver in use: i915
>          Kernel modules: i915
>
> 00:13.0 SATA controller: Intel Corporation Atom Processor E3800 Series
> SATA AHCI Controller (rev 11) (prog-if 01 [AHCI 1.0])
>          Subsystem: Intel Corporation Atom Processor E3800 Series SATA
> AHCI Controller
>          Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 91
>          I/O ports at e070 [size=8]
>          I/O ports at e060 [size=4]
>          I/O ports at e050 [size=8]
>          I/O ports at e040 [size=4]
>          I/O ports at e020 [size=32]
>          Memory at b0b17000 (32-bit, non-prefetchable) [size=2K]
>          Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
>          Capabilities: [70] Power Management version 3
>          Capabilities: [a8] SATA HBA v1.0
>          Kernel driver in use: ahci
>          Kernel modules: ahci
>
> 00:14.0 USB controller: Intel Corporation Atom Processor
> Z36xxx/Z37xxx, Celeron N2000 Series USB xHCI (rev 11) (prog-if 30
> [XHCI])
>          Subsystem: Intel Corporation Atom Processor Z36xxx/Z37xxx,
> Celeron N2000 Series USB xHCI
>          Flags: bus master, medium devsel, latency 0, IRQ 90
>          Memory at b0b00000 (64-bit, non-prefetchable) [size=64K]
>          Capabilities: [70] Power Management version 2
>          Capabilities: [80] MSI: Enable+ Count=1/8 Maskable- 64bit+
>          Kernel driver in use: xhci_hcd
>
> 00:17.0 SD Host controller: Intel Corporation Atom Processor E3800
> Series eMMC 4.5 Controller (rev 11) (prog-if 01)
>          Flags: bus master, fast devsel, latency 0, IRQ 23
>          Memory at b0b16000 (32-bit, non-prefetchable) [size=4K]
>          Memory at b0b15000 (32-bit, non-prefetchable) [size=4K]
>          Capabilities: [80] Power Management version 3
>          Kernel driver in use: sdhci-pci
>          Kernel modules: sdhci_pci
>
> 00:1a.0 Encryption controller: Intel Corporation Atom Processor
> Z36xxx/Z37xxx Series Trusted Execution Engine (rev 11)
>          Subsystem: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series Trusted Execution Engine
>          Flags: bus master, fast devsel, latency 0, IRQ 98
>          Memory at b0900000 (32-bit, non-prefetchable) [size=1M]
>          Memory at b0800000 (32-bit, non-prefetchable) [size=1M]
>          Capabilities: [80] Power Management version 3
>          Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit-
>          Kernel driver in use: mei_txe
>          Kernel modules: mei_txe
>
> 00:1b.0 Audio device: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series High Definition Audio Controller (rev 11)
>          Subsystem: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series High Definition Audio Controller
>          Flags: bus master, fast devsel, latency 0, IRQ 10
>          Memory at b0b10000 (64-bit, non-prefetchable) [size=16K]
>          Capabilities: [50] Power Management version 2
>          Capabilities: [60] MSI: Enable- Count=1/1 Maskable- 64bit+
>          Kernel modules: snd_hda_intel
>
> 00:1c.0 PCI bridge: Intel Corporation Atom Processor E3800 Series PCI
> Express Root Port 1 (rev 11) (prog-if 00 [Normal decode])
>          Flags: bus master, fast devsel, latency 0, IRQ 87
>          Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
>          I/O behind bridge: 00001000-00001fff [size=4K]
>          Memory behind bridge: b0400000-b07fffff [size=4M]
>          Prefetchable memory behind bridge: [disabled]
>          Capabilities: [40] Express Root Port (Slot+), MSI 00
>          Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
>          Capabilities: [90] Subsystem: Intel Corporation Atom Processor
> E3800 Series PCI Express Root Port 1
>          Capabilities: [a0] Power Management version 3
>          Kernel driver in use: pcieport
>
> 00:1c.2 PCI bridge: Intel Corporation Atom Processor E3800 Series PCI
> Express Root Port 3 (rev 11) (prog-if 00 [Normal decode])
>          Flags: bus master, fast devsel, latency 0, IRQ 88
>          Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
>          I/O behind bridge: 00002000-00002fff [size=4K]
>          Memory behind bridge: [disabled]
>          Prefetchable memory behind bridge: [disabled]
>          Capabilities: [40] Express Root Port (Slot+), MSI 00
>          Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
>          Capabilities: [90] Subsystem: Intel Corporation Atom Processor
> E3800 Series PCI Express Root Port 3
>          Capabilities: [a0] Power Management version 3
>          Kernel driver in use: pcieport
>
> 00:1c.3 PCI bridge: Intel Corporation Atom Processor E3800 Series PCI
> Express Root Port 4 (rev 11) (prog-if 00 [Normal decode])
>          Flags: bus master, fast devsel, latency 0, IRQ 89
>          Bus: primary=00, secondary=03, subordinate=03, sec-latency=0
>          I/O behind bridge: 0000d000-0000dfff [size=4K]
>          Memory behind bridge: b0a00000-b0afffff [size=1M]
>          Prefetchable memory behind bridge: [disabled]
>          Capabilities: [40] Express Root Port (Slot+), MSI 00
>          Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
>          Capabilities: [90] Subsystem: Intel Corporation Atom Processor
> E3800 Series PCI Express Root Port 4
>          Capabilities: [a0] Power Management version 3
>          Kernel driver in use: pcieport
>
> 00:1f.0 ISA bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series Power Control Unit (rev 11)
>          Subsystem: Intel Corporation Atom Processor Z36xxx/Z37xxx
> Series Power Control Unit
>          Flags: bus master, medium devsel, latency 0
>          Capabilities: [e0] Vendor Specific Information: Len=0c <?>
>          Kernel driver in use: lpc_ich
>          Kernel modules: lpc_ich
>
> 00:1f.3 SMBus: Intel Corporation Atom Processor E3800 Series SMBus
> Controller (rev 11)
>          Subsystem: Intel Corporation Atom Processor E3800 Series SMBus
> Controller
>          Flags: medium devsel, IRQ 18
>          Memory at b0b14000 (32-bit, non-prefetchable) [size=32]
>          I/O ports at e000 [size=32]
>          Capabilities: [50] Power Management version 3
>          Kernel driver in use: i801_smbus
>          Kernel modules: i2c_i801

The i2c_i801 driver uses a custom operation region handler to intercept ACPI accesses
to the smbus controller registers, maybe this could be the reason for the timeouts.

I CCed the maintainers of this driver. Maybe they can help us here.

Thanks,
Armin Wolf

> 01:00.0 RAM memory: PLDA Device 5555
>          Subsystem: Device 4000:0000
>          Flags: fast devsel, IRQ 11
>          Memory at b0400000 (32-bit, non-prefetchable) [virtual] [size=4M]
>          Capabilities: [40] Power Management version 3
>          Capabilities: [48] MSI: Enable- Count=1/1 Maskable- 64bit-
>          Capabilities: [60] Express Endpoint, MSI 00
>
> 03:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network
> Connection (rev 03)
>          Flags: bus master, fast devsel, latency 0, IRQ 19
>          Memory at b0a00000 (32-bit, non-prefetchable) [size=512K]
>          I/O ports at d000 [size=32]
>          Memory at b0a80000 (32-bit, non-prefetchable) [size=16K]
>          Capabilities: [40] Power Management version 3
>          Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
>          Capabilities: [70] MSI-X: Enable+ Count=5 Masked-
>          Capabilities: [a0] Express Endpoint, MSI 00
>          Capabilities: [100] Advanced Error Reporting
>          Capabilities: [140] Device Serial Number 00-30-64-ff-ff-a2-59-aa
>          Capabilities: [1a0] Transaction Processing Hints
>          Kernel driver in use: igb
>          Kernel modules: igb
>
> > Thanks,
> > Armin Wolf
> >
> > > > > 4. Is there a recommended workaround to mitigate this issue?
> > > > You can check if a BIOS update is available for your device.
> > > >
> > > > > 4. How can I debug this further?I can enable additional ACPI debugging
> > > > > logs or provide dumps of ACPI tables if necessary.
> > > > I can take a look at the \_SB.PCI0.SBUS.RDWD method inside the ACPI table dumps
> > > > to see where the error is coming from.
> > > >
> > > > Thanks,
> > > > Armin Wolf
> > > >
> > > > > Any guidance on resolving or further diagnosing this issue would be
> > > > > highly appreciated.
> > > > >
> > > > > Best regards,
> > > > > Naveen