usb: add usb port auto power off mechanism
This patch is to add usb port auto power off mechanism. When usb device is suspending, usb core will suspend usb port and usb port runtime pm callback will clear PORT_POWER feature to power off port if all conditions were met. These conditions are remote wakeup disable, pm qos NO_POWER_OFF flag clear and persist enable. When it resumes, power on port again. Add did_runtime_put in the struct usb_port to ensure pm_runtime_get/put(portdev) to be called pairedly. Set did_runtime_put to true when call pm_runtime_put(portdev) during suspending. The pm_runtime_get(portdev) only will be called when did_runtime_put is set to true during resuming. Set did_runtime_put to false after calling pm_runtime_get(portdev). Make clear_port_feature() and hdev_to_hub() as global symbol. Rename clear_port_feature() to usb_clear_port_feature() and hdev_to_hub() to usb_hub_to_struct_hub(). Extend hub_port_debounce() with the fuction of debouncing to be connected. Add two wraps: hub_port_debounce_be_connected() and hub_port_debouce_be_stable(). Increase HUB_DEBOUNCE_TIMEOUT to 2000 because some usb ssds needs around 1.5 or more to make the hub port status to be connected steadily after being powered off and powered on. Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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