UBUNTU: SAUCE: USB: Disable USB2 LPM at shutdown

BugLink: https://bugs.launchpad.net/bugs/1757218
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>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 1a01e9ad38049c7928a618a9941d8950cf21556c..032683ac4db4e88683a6b91001003c23de6a844b 100644 (file)
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -242,6 +242,14 @@ 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,
@@ -258,6 +266,7 @@ 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)