diff options
| author | Breno Leitao <leitao@debian.org> | 2026-04-20 12:27:13 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2026-04-27 15:39:32 +0300 |
| commit | 3ea4415015d690a51a3fb1f98dfc9a02f88f7bc4 (patch) | |
| tree | 296a51023df7415d425a6cadb76285769fa3b98c | |
| parent | caecde119e341acd9819cbc1c54edf6caa6c6389 (diff) | |
| download | linux-3ea4415015d690a51a3fb1f98dfc9a02f88f7bc4.tar.xz | |
ACPI: arm64: cpuidle: Tolerate platforms with no deep PSCI idle states
Commit cac173bea57d ("ACPI: processor: idle: Rework the handling of
acpi_processor_ffh_lpi_probe()") moved the acpi_processor_ffh_lpi_probe()
call from acpi_processor_setup_cpuidle_dev(), where its return value was
ignored, to acpi_processor_get_power_info(), where it is now treated as
a hard failure. As a result, platforms where psci_acpi_cpu_init_idle()
returned -ENODEV stopped registering any cpuidle states, forcing CPUs to
busy-poll when idle.
On NVIDIA Grace (aarch64) systems with PSCIv1.1, pr->power.count is 1
(only WFI, no deep PSCI states beyond it), so the previous
"count = pr->power.count - 1; if (count <= 0) return -ENODEV;" check
returned -ENODEV for all 72 CPUs and disabled cpuidle entirely.
The lpi_states count is already validated in acpi_processor_get_lpi_info(),
so the check here is redundant. Simplify the loop to iterate over
lpi_states[1..power.count). When only WFI is present, the loop body
simply does not execute and the function returns 0, which is the correct
outcome: there is nothing to validate for FFH and no error to report.
Suggested-by: Huisong Li <lihuisong@huawei.com>
Cc: stable@vger.kernel.org
Fixes: cac173bea57d ("ACPI: processor: idle: Rework the handling of acpi_processor_ffh_lpi_probe()")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | drivers/acpi/arm64/cpuidle.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/acpi/arm64/cpuidle.c b/drivers/acpi/arm64/cpuidle.c index 801f9c450142..c68a5db8ebba 100644 --- a/drivers/acpi/arm64/cpuidle.c +++ b/drivers/acpi/arm64/cpuidle.c @@ -16,7 +16,7 @@ static int psci_acpi_cpu_init_idle(unsigned int cpu) { - int i, count; + int i; struct acpi_lpi_state *lpi; struct acpi_processor *pr = per_cpu(processors, cpu); @@ -30,14 +30,10 @@ static int psci_acpi_cpu_init_idle(unsigned int cpu) if (!psci_ops.cpu_suspend) return -EOPNOTSUPP; - count = pr->power.count - 1; - if (count <= 0) - return -ENODEV; - - for (i = 0; i < count; i++) { + for (i = 1; i < pr->power.count; i++) { u32 state; - lpi = &pr->power.lpi_states[i + 1]; + lpi = &pr->power.lpi_states[i]; /* * Only bits[31:0] represent a PSCI power_state while * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification |