On some AMD platforms the platform _OSC negotiation will lead to
`osc_pc_lpi_support_confirmed` being set and because the ACPI tables are
populated with `_LPI` entries the kernel will attempt to enable LPI.
On non-ARM kernels LPI is not supported and both
`acpi_processor_ffh_lpi_probe` and
`acpi_processor_ffh_lpi_enter` will return error codes.
When this happens there is no recourse though; the cpuidle code does
not switch to `_CST` mode, but rather it will continue to behave as though
LPI has been enabled and the CPU will remain in a high power state.
This patch series shifts the checks around while enabling LPI to detect
this situation and let the system continue to set up in _CST mode.
Mario Limonciello (2):
PSCI: cpuidle: Move the `has_lpi` check to the beginning of the
function
ACPI: processor idle: Check for architectural support for LPI
arch/arm64/kernel/cpuidle.c | 6 +++---
drivers/acpi/processor_idle.c | 15 ++++++++++-----
2 files changed, 13 insertions(+), 8 deletions(-)
--
2.34.1
