Phase I (LG Gram 16 (2025) / Arrow Lake-H S-state work).
This commit implements the full Linux 7.1 S-state AML method
sequence in userspace acpid, plus stubs for s2idle (Modern
Standby). The kernel-side s2idle wire (new AcpiVerb variants
EnterS2Idle / ExitS2Idle) is the next step; see
local/docs/SLEEP-IMPLEMENTATION-PLAN.md for the gap analysis.
Changes:
* FACS: add set_waking_vector / set_x_waking_vector methods.
These let acpid write the firmware waking vector for S3
resume, mirroring Linux 7.1
drivers/acpi/acpica/hwxfsleep.c:92
(acpi_set_firmware_waking_vector).
* FACS access: add facs_mut() mutable accessor on
AcpiContext (single-writer by construction).
* AML methods: add set_system_status_indicator() that calls
\_SI._SST(n). The canonical values are 0=working, 1=waking,
2=sleeping, 3=sleep-context, 7=indicator-off. Mirrors Linux
ACPI 6.5 §6.5.1 (System Status Indicator).
* wake_from_s_state(): wrap \_WAK(n) with the full Linux wake
sequence (\_SI._SST(2) before, \_SI._SST(1) after). Mirrors
drivers/acpi/acpica/hwsleep.c:255-314.
* enter_sleep_state(): only call \_TTS here; \_PTS + \_SST +
PM1 writes remain in set_global_s_state (Phase D, no
duplication).
* s2idle: add enter_s2idle() and exit_s2idle() methods on
AcpiContext. These prepare/finish the s2idle path on systems
without \_S3 (LG Gram 2025). Currently a no-op for the kernel
coordination; the AML \_WAK(0) sequence runs via
wake_from_s_state(0) on exit.
Cross-references:
* drivers/acpi/sleep.c (Linux 7.1) — acpi_suspend_begin/enter
* drivers/acpi/acpica/hwxfsleep.c — acpi_enter_sleep_state_prep
* drivers/acpi/acpica/hwsleep.c — acpi_hw_legacy_wake
* kernel/power/suspend.c — s2idle_loop, s2idle_state
* drivers/acpi/acpica/hwesleep.c — acpi_hw_execute_sleep_method
Files changed:
drivers/acpid/src/acpi.rs (+203 -14)
Red Bear OS
5d2d114bf9