On Friday, September 28, 2018 10:54:02 AM CEST Rajneesh Bhardwaj wrote: > ACPI Low Power S0 Idle capabilities are announced via FADT table and can > be used to inform the kernel about the presence of one or more Low Power > Idle (LPI) entries as descried in LPIT table. LPIT table can exist > independently even if the FADT S0 Idle flag is not set and thus it could > confuse user since the following cpuidle attributes are created. > > /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us > /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us > > Presence or absence of above attributes could mean that the given > platform supports S0ix state or not. > > This change allows to create the above cpuidle attributes only if > FADT table supports Low Power S0 Idle. > > Cc: Rafael J . Wysocki <[email protected]> > Cc: Srinivas Pandruvada <[email protected]> > Signed-off-by: Rajneesh Bhardwaj <[email protected]> > --- > drivers/acpi/acpi_lpit.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/acpi/acpi_lpit.c b/drivers/acpi/acpi_lpit.c > index cf4fc0161164..e43cb71b6972 100644 > --- a/drivers/acpi/acpi_lpit.c > +++ b/drivers/acpi/acpi_lpit.c > @@ -117,11 +117,17 @@ static void lpit_update_residency(struct > lpit_residency_info *info, > if (!info->iomem_addr) > return; > > + if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)) > + return; > + > /* Silently fail, if cpuidle attribute group is not present */ > sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj, > > &dev_attr_low_power_idle_system_residency_us.attr, > "cpuidle"); > } else if (info->gaddr.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { > + if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)) > + return; > + > /* Silently fail, if cpuidle attribute group is not present */ > sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj, > > &dev_attr_low_power_idle_cpu_residency_us.attr, >
Applied, thanks!
