diff options
| author | Lan Tianyu <tianyu.lan@intel.com> | 2013-01-22 21:26:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-25 19:14:20 +0100 |
| commit | f6cced1a08b475c5ac946823bb057714be7af4f6 (patch) | |
| tree | 68a5d9b213296d772cbc6ff1aaccf4cb3289a894 /drivers/usb/core | |
| parent | usb: add usb port auto power off mechanism (diff) | |
| download | linux-f6cced1a08b475c5ac946823bb057714be7af4f6.tar.xz linux-f6cced1a08b475c5ac946823bb057714be7af4f6.zip | |
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.c | 11 |
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) |