https://bugzilla.kernel.org/show_bug.cgi?id=221987
Bug ID: 221987
Summary: ASUS TUF GAMING B550-PRO: duplicate ACPI _PLD group
position for AMD 1022:43ee causes USB peer collision
Product: ACPI
Version: 2.5
Hardware: AMD
OS: Linux
Status: NEW
Severity: normal
Priority: P3
Component: Config-Tables
Assignee: [email protected]
Reporter: [email protected]
Regression: No
Created attachment 310815
--> https://bugzilla.kernel.org/attachment.cgi?id=310815&action=edit
ACPI DSDT excerpts, sysfs peer mappings, controller information, and boot
warning
Hardware:
ASUS TUF GAMING B550-PRO
BIOS 3644, dated 2026-08-19
AMD 500 Series Chipset USB 3.1 xHCI Controller [1022:43ee]
Subsystem [1b21:1142]
Kernel: 7.2.3-2-MANJARO
At boot the kernel reports:
usb: port power management may be unreliable
The warning occurs while initializing xHCI controller 0000:02:00.0.
The ACPI node for this controller is:
\_SB_.PCI0.GPP1.PTXH
Sysfs exposes the following relevant port locations:
usb1-port1 hotplug location=0x8000000a
usb1-port2 not used location=0x8000000b
usb2-port1 hotplug location=0x8000000a
usb2-port2 hotplug location=0x8000000a
usb1-port1 and usb2-port1 are paired successfully.
usb2-port2 remains unpaired.
Ports 3 and 4 map correctly:
usb1-port3 / usb2-port3 = 0x8000000c
usb1-port4 / usb2-port4 = 0x8000000d
A second xHCI controller in the same machine (0000:0a:00.3) has
completely symmetric USB2/USB3 peer mappings for ports 1-4.
I dumped and disassembled the DSDT.
Under:
\_SB_.PCI0.GPP1.PTXH.RHUB
UPGP() selects package PT2 when XDID == 0x43EE:
ElseIf (... || (XDID == 0x43EE))
{
...
USBP [Local0] = DerefOf (PT2 [Local0])
}
PT2 is defined beginning with:
0x0A,
0x0A,
0x0C,
0x0D,
0x0A,
0x0B,
0x0C,
0x0D,
The corresponding _PLD methods use:
POT1 -> USBP[0]
POT2 -> USBP[1]
POT5 -> USBP[4]
POT6 -> USBP[5]
GPLD() writes that value into the _PLD Group Position field.
Thus the firmware produces:
POT1 = 0x0A
POT2 = 0x0A
POT5 = 0x0A
POT6 = 0x0B
This exactly matches the duplicate location exposed by Linux and the
failed peer association.
For comparison, the PT4 package begins with:
0x0A, 0x0B, 0x0C, 0x0D
This strongly suggests that PT2[1] = 0x0A is an erroneous firmware
entry, with 0x0B likely intended.
This appears related in area to bug 221957, which also involves ASUS
PTXH.RHUB / UPGP USB _PLD generation, but the defect here is different:
the 0x43EE branch exists and executes; PT2 itself contains the duplicate
group-position value.
I have not applied any ACPI override or firmware modification.
Separately, the same 0000:02:00.0 xHCI controller reports:
xHC error in resume, USBSTS 0x401, Reinit
after ACPI S3 resume on this system. I have not established that the
resume issue is causally related to this _PLD defect.
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