Commit 582ee9c5 authored Aug 05, 2019 by Kai-Heng Feng Committed by Greg Kroah-Hartman Aug 05, 2019

USB: Disable USB2 LPM at shutdown

The QCA Rome USB Bluetooth controller has several issues once LPM gets
enabled:
- Fails to get enumerated in coldboot. [1]
- Drains more power (~ 0.2W) when the system is in S5. [2]
- Disappears after a warmboot. [2]

The issue happens because the device lingers at LPM L1 in S5, so device
can't get enumerated even after a reboot.

Disable LPM at shutdown to solve the issue.

[1] https://bugs.launchpad.net/bugs/1757218
[2] https://patchwork.kernel.org/patch/10607097/



Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20190805142412.23965-1-kai.heng.feng@canonical.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent d3523b63

drivers/usb/core/port.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -285,6 +285,14 @@ static int usb_port_runtime_suspend(struct device *dev)
		}
		#endif

		static void usb_port_shutdown(struct device *dev)
		{
		struct usb_port *port_dev = to_usb_port(dev);

		if (port_dev->child)
		usb_disable_usb2_hardware_lpm(port_dev->child);
		}

		static const struct dev_pm_ops usb_port_pm_ops = {
		#ifdef CONFIG_PM
		.runtime_suspend = usb_port_runtime_suspend,
		@@ -301,6 +309,7 @@ struct device_type usb_port_device_type = {
		static struct device_driver usb_port_driver = {
		.name = "usb",
		.owner = THIS_MODULE,
		.shutdown = usb_port_shutdown,
		};

		static int link_peers(struct usb_port left, struct usb_port right)

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