[PATCH v9 1/7] ACPI: scan: Obtain device's desired enumeration power state
From: Sakari Ailus <sakari.ailus@linux.intel.com>
Date: 2021-01-28 23:32:01
Also in:
linux-acpi, linux-media, lkml
Subsystem:
acpi, acpi component architecture (acpica), the rest · Maintainers:
"Rafael J. Wysocki", Saket Dumbre, Linus Torvalds
Store a device's desired enumeration power state in struct acpi_device_power_flags during acpi_device object's initialisation. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> --- drivers/acpi/scan.c | 6 ++++++ include/acpi/acpi_bus.h | 3 ++- 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 1d7a02ee45e05..b077c645c9845 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c@@ -987,6 +987,8 @@ static void acpi_bus_init_power_state(struct acpi_device *device, int state) static void acpi_bus_get_power_flags(struct acpi_device *device) { + unsigned long long pre; + acpi_status status; u32 i; /* Presence of _PS0|_PR0 indicates 'power manageable' */
@@ -1008,6 +1010,10 @@ static void acpi_bus_get_power_flags(struct acpi_device *device) if (acpi_has_method(device->handle, "_DSW")) device->power.flags.dsw_present = 1; + status = acpi_evaluate_integer(device->handle, "_PRE", NULL, &pre); + if (ACPI_SUCCESS(status) && !pre) + device->power.flags.allow_low_power_probe = 1; + /* * Enumerate supported power management states */
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 02a716a0af5d4..020b850120883 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h@@ -258,7 +258,8 @@ struct acpi_device_power_flags { u32 power_removed:1; /* Optimize Dx->D0 */ u32 ignore_parent:1; /* Power is independent of parent power state */ u32 dsw_present:1; /* _DSW present? */ - u32 reserved:26; + u32 allow_low_power_probe:1; /* Allow low power state in device probe */ + u32 reserved:25; }; struct acpi_device_power_state {
--
2.20.1