It is possible for ACPI _CST to return only one ACPI C-state, for example, when deep cstate disabled in the BIOS. And it is better for the acpi_idle driver to probe in this case as well for consistency. Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> --- drivers/acpi/processor_idle.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index dcc289e30166..75534c5b5433 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -308,11 +308,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) if (ret) return ret; - /* - * It is expected that there will be at least 2 states, C1 and - * something else (C2 or C3), so fail if that is not the case. - */ - if (pr->power.count < 2) + if (!pr->power.count) return -EFAULT; pr->flags.has_cst = 1; @@ -468,8 +464,7 @@ static int acpi_processor_get_cstate_info(struct acpi_processor *pr) for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { if (pr->power.states[i].valid) { pr->power.count = i; - if (pr->power.states[i].type >= ACPI_STATE_C2) - pr->flags.power = 1; + pr->flags.power = 1; } } -- 2.17.1