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authorMika Westerberg <mika.westerberg@linux.intel.com>2013-10-10 14:28:46 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-10-11 04:23:14 +0400
commit644f17ad7fc12768cd619532383343e514eab2ac (patch)
treed862d7b92d113ccacc529aeabff9f7ab0af3d6b1 /include/acpi
parent360818b83f8652655558d0ab0d61c2d98a1cb631 (diff)
downloadlinux-644f17ad7fc12768cd619532383343e514eab2ac.tar.xz
ACPI / PM: allow child devices to ignore parent power state
Some serial buses like I2C and SPI don't require that the parent device is in D0 before any of its children transitions to D0, but instead the parent device can control its own power independently from the children. This does not follow the ACPI specification as it requires the parent to be powered on before its children. However, Windows seems to ignore this requirement so I think we can do the same in Linux. Implement this by adding a new power flag 'ignore_parent' to struct acpi_device. If this flag is set the ACPI core ignores checking of the parent device power state when the device is powered on/off. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/acpi')
-rw-r--r--include/acpi/acpi_bus.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 02e113bb8b7d..e830ab029340 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -222,7 +222,8 @@ struct acpi_device_power_flags {
u32 power_resources:1; /* Power resources */
u32 inrush_current:1; /* Serialize Dx->D0 */
u32 power_removed:1; /* Optimize Dx->D0 */
- u32 reserved:28;
+ u32 ignore_parent:1; /* Power is independent of parent power state */
+ u32 reserved:27;
};
struct acpi_device_power_state {