USB/xHCI: Enable USB 3.0 hub remote wakeup.

USB 3.0 hubs have a different remote wakeup policy than USB 2.0 hubs.
USB 2.0 hubs, once they have remote wakeup enabled, will always send
remote wakes when anything changes on a port.

However, USB 3.0 hubs have a per-port remote wake up policy that is off
by default.  The Set Feature remote wake mask can be changed for any
port, enabling remote wakeup for a connect, disconnect, or overcurrent
event, much like EHCI and xHCI host controller "wake on" port status
bits.  The bits are cleared to zero on the initial hub power on, or
after the hub has been reset.

Without this patch, when a USB 3.0 hub gets suspended, it will not send
a remote wakeup on device connect or disconnect.  This would show up to
the user as "dead ports" unless they ran lsusb -v (since newer versions
of lsusb use the sysfs files, rather than sending control transfers).

Change the hub driver's suspend method to enable remote wake up for
disconnect, connect, and overcurrent for all ports on the hub.  Modify
the xHCI driver's roothub code to handle that request, and set the "wake
on" bits in the port status registers accordingly.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/core/hub.c

@@ -2731,6 +2731,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 	struct usb_hub		*hub = usb_get_intfdata (intf);
 	struct usb_device	*hdev = hub->hdev;
 	unsigned		port1;
+	int			status;
 
 	/* Warn if children aren't already suspended */
 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
@@ -2743,6 +2744,17 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 				return -EBUSY;
 		}
 	}
+	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
+		/* Enable hub to send remote wakeup for all ports. */
+		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
+			status = set_port_feature(hdev,
+					port1 |
+					USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
+					USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
+					USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
+					USB_PORT_FEAT_REMOTE_WAKE_MASK);
+		}
+	}
 
 	dev_dbg(&intf->dev, "%s\n", __func__);
 

drivers/usb/host/xhci-hub.c

@@ -422,6 +422,32 @@ void xhci_set_link_state(struct xhci_hcd *xhci, __le32 __iomem **port_array,
 	xhci_writel(xhci, temp, port_array[port_id]);
 }
 
+void xhci_set_remote_wake_mask(struct xhci_hcd *xhci,
+		__le32 __iomem **port_array, int port_id, u16 wake_mask)
+{
+	u32 temp;
+
+	temp = xhci_readl(xhci, port_array[port_id]);
+	temp = xhci_port_state_to_neutral(temp);
+
+	if (wake_mask & USB_PORT_FEAT_REMOTE_WAKE_CONNECT)
+		temp |= PORT_WKCONN_E;
+	else
+		temp &= ~PORT_WKCONN_E;
+
+	if (wake_mask & USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT)
+		temp |= PORT_WKDISC_E;
+	else
+		temp &= ~PORT_WKDISC_E;
+
+	if (wake_mask & USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT)
+		temp |= PORT_WKOC_E;
+	else
+		temp &= ~PORT_WKOC_E;
+
+	xhci_writel(xhci, temp, port_array[port_id]);
+}
+
 /* Test and clear port RWC bit */
 void xhci_test_and_clear_bit(struct xhci_hcd *xhci, __le32 __iomem **port_array,
 				int port_id, u32 port_bit)
@@ -448,6 +474,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 	int slot_id;
 	struct xhci_bus_state *bus_state;
 	u16 link_state = 0;
+	u16 wake_mask = 0;
 
 	max_ports = xhci_get_ports(hcd, &port_array);
 	bus_state = &xhci->bus_state[hcd_index(hcd)];
@@ -593,6 +620,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 	case SetPortFeature:
 		if (wValue == USB_PORT_FEAT_LINK_STATE)
 			link_state = (wIndex & 0xff00) >> 3;
+		if (wValue == USB_PORT_FEAT_REMOTE_WAKE_MASK)
+			wake_mask = wIndex & 0xff00;
 		wIndex &= 0xff;
 		if (!wIndex || wIndex > max_ports)
 			goto error;
@@ -703,6 +732,14 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			temp = xhci_readl(xhci, port_array[wIndex]);
 			xhci_dbg(xhci, "set port reset, actual port %d status  = 0x%x\n", wIndex, temp);
 			break;
+		case USB_PORT_FEAT_REMOTE_WAKE_MASK:
+			xhci_set_remote_wake_mask(xhci, port_array,
+					wIndex, wake_mask);
+			temp = xhci_readl(xhci, port_array[wIndex]);
+			xhci_dbg(xhci, "set port remote wake mask, "
+					"actual port %d status  = 0x%x\n",
+					wIndex, temp);
+			break;
 		case USB_PORT_FEAT_BH_PORT_RESET:
 			temp |= PORT_WR;
 			xhci_writel(xhci, temp, port_array[wIndex]);
@@ -883,6 +920,10 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 			t2 |= PORT_LINK_STROBE | XDEV_U3;
 			set_bit(port_index, &bus_state->bus_suspended);
 		}
+		/* USB core sets remote wake mask for USB 3.0 hubs,
+		 * including the USB 3.0 roothub, but only if CONFIG_USB_SUSPEND
+		 * is enabled, so also enable remote wake here.
+		 */
 		if (hcd->self.root_hub->do_remote_wakeup) {
 			if (t1 & PORT_CONNECT) {
 				t2 |= PORT_WKOC_E | PORT_WKDISC_E;

include/linux/usb/ch11.h

@@ -76,6 +76,11 @@
 #define USB_PORT_FEAT_C_BH_PORT_RESET		29
 #define USB_PORT_FEAT_FORCE_LINKPM_ACCEPT	30
 
+/* USB 3.0 hub remote wake mask bits, see table 10-14 */
+#define USB_PORT_FEAT_REMOTE_WAKE_CONNECT	(1 << 8)
+#define USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT	(1 << 9)
+#define USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT	(1 << 10)
+
 /*
  * Hub Status and Hub Change results
  * See USB 2.0 spec Table 11-19 and Table 11-20