https://bugzilla.kernel.org/show_bug.cgi?id=221328
Bug ID: 221328
Summary: ACPI: FADT LOW_POWER_S0_IDLE_CAPABLE incorrectly set
on BANGHO MAX L5 R7 Z3 (Clevo/Tongfang AMD 7730U) —
blocks S3 despite _S3_ being defined in DSDT
Product: ACPI
Version: 2.5
Hardware: Intel
OS: Linux
Status: NEW
Severity: normal
Priority: P3
Component: Power-Sleep-Wake
Assignee: [email protected]
Reporter: [email protected]
Regression: No
Hardware: BANGHO MAX L5 R7 Z3 (Clevo/Tongfang ODM)
CPU: AMD Ryzen 7 7730U (Barcelo)
BIOS: Insyde Corp v2.70, version 1.07.30RPC1, date 02/28/2025
Kernel: 6.18.7 (Pop!_OS 24.04)
PROBLEM:
The system FADT has LOW_POWER_S0_IDLE_CAPABLE (bit 21) set to 1, which
causes Linux to suppress S3 and expose only s2idle:
cat /sys/power/mem_sleep → [s2idle]
ACPI: PM: (supports S0 S4 S5) ← S3 absent
However, the DSDT fully defines _S3_ with valid sleep type values:
_S3_ found at DSDT offset 0xd49
Bytes: 5f53335f1208040a030a0300 → package {3, 3, 0, 0}
_S0_: present, _S3_: present, _S4_: present, _S5_: present
FADT flags: 0x0020c5bd
Bit 21 (LOW_POWER_S0_IDLE_CAPABLE) = 1 ← incorrectly set
Bit 20 (HW_REDUCED_ACPI) = 0
This is a firmware misconfiguration: the AMD AGESA layer correctly
generated _S3_ in the DSDT, but the Insyde BIOS (BANGHO/Clevo ODM)
incorrectly set LOW_POWER_S0_IDLE_CAPABLE, likely copied from a
Windows Modern Standby certification template.
PROOF OF FIX:
Using Smokeless UMAF to change AMD PBS → "S3/Modern Standby Support"
from Modern Standby to S3 Enable clears LOW_POWER_S0_IDLE_CAPABLE and
immediately fixes the issue:
cat /sys/power/mem_sleep → s2idle [deep]
ACPI: PM: (supports S0 S3 S4 S5) ← S3 now present
S3 suspend and resume works correctly after this change.
REQUESTED FIX:
Add a kernel ACPI quirk for this DMI entry to clear
LOW_POWER_S0_IDLE_CAPABLE, matching similar existing quirks:
DMI_MATCH(DMI_SYS_VENDOR, "BANGHO"),
DMI_MATCH(DMI_PRODUCT_NAME, "MAX L5 R7 Z3"),
This would fix the issue for all Linux users on this hardware without
requiring BIOS modification via third-party tools.
A secondary issue also present: amdgpu reports "Runtime PM not
available" causing s2idle resume hangs — workaround: amdgpu.runpm=0
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