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authorLan Tianyu <tianyu.lan@intel.com>2013-01-23 04:26:31 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-25 10:14:20 -0800
commitf6cced1a08b475c5ac946823bb057714be7af4f6 (patch)
tree68a5d9b213296d772cbc6ff1aaccf4cb3289a894 /drivers/usb/core
parentad493e5e580546e6c3024b76a41535476da1546a (diff)
usb: expose usb port's pm qos flags to user space
This patch is to expose usb port's pm qos flags(pm_qos_no_power_off, pm_qos_remote_wakeup) to user space. User can set pm_qos_no_power_off flag to prohibit the port from being powered off. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/port.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 280433d80887..9a15b26944ec 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -67,6 +67,7 @@ static void usb_port_device_release(struct device *dev)
{
struct usb_port *port_dev = to_usb_port(dev);
+ dev_pm_qos_hide_flags(dev);
usb_acpi_unregister_power_resources(dev);
kfree(port_dev);
}
@@ -176,7 +177,15 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
goto error_register;
pm_runtime_set_active(&port_dev->dev);
- pm_runtime_enable(&port_dev->dev);
+
+ /* It would be dangerous if user space couldn't
+ * prevent usb device from being powered off. So don't
+ * enable port runtime pm if failed to expose port's pm qos.
+ */
+ if (!dev_pm_qos_expose_flags(&port_dev->dev,
+ PM_QOS_FLAG_NO_POWER_OFF))
+ pm_runtime_enable(&port_dev->dev);
+
retval = usb_acpi_register_power_resources(&port_dev->dev);
if (retval && retval != -ENODEV)