Commit 98a4f1ff authored Jul 03, 2013 by Lan Tianyu Committed by Sarah Sharp Aug 15, 2013

usb: don't check pm qos NO_POWER_OFF flag in usb_port_suspend()

The pm qos NO_POWER_OFF flag is checked twice during usb device suspend
to see if the usb port power off condition is met. This is redundant and
also will prevent the port from being powered off if the NO_POWER_OFF
flag is changed to 1 from 0 after the device was already suspended.

More detail in the following link.
	http://marc.info/?l=linux-usb&m=136543949130865&w=2



This patch should be backported to kernels as old as 3.7, that
contain the commit f7ac7787 "usb/acpi:
Use ACPI methods to power off ports."

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

parent aa5ceae2

drivers/usb/core/hub.c

+2 −12

Original line number	Diff line number	Diff line
		@@ -3043,20 +3043,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
		usb_set_device_state(udev, USB_STATE_SUSPENDED);
		}

		/*
		* Check whether current status meets the requirement of
		* usb port power off mechanism
		*/
		if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled) {
		enum pm_qos_flags_status pm_qos_stat;

		pm_qos_stat = dev_pm_qos_flags(&port_dev->dev,
		PM_QOS_FLAG_NO_POWER_OFF);
		if (pm_qos_stat != PM_QOS_FLAGS_ALL) {
		pm_runtime_put_sync(&port_dev->dev);
		port_dev->did_runtime_put = true;
		}
		}

		usb_mark_last_busy(hub->hdev);
		return status;