usbcore: Refine USB3.0 device suspend and resume

In the past, we use USB2.0 request to suspend and resume a USB3.0 device.
Actually, USB3.0 hub does not support Set/Clear PORT_SUSPEND request,
instead, it uses Set PORT_LINK_STATE request. This patch makes USB3.0 device
suspend/resume comply with USB3.0 specification.

This patch fixes the issue that USB3.0 device can not be suspended when
connected to a USB3.0 external hub.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/core/hub.c

@@ -2307,14 +2307,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 	}
 
 	/* see 7.1.7.6 */
-	/* Clear PORT_POWER if it's a USB3.0 device connected to USB 3.0
-	 * external hub.
-	 * FIXME: this is a temporary workaround to make the system able
-	 * to suspend/resume.
-	 */
-	if ((hub->hdev->parent != NULL) && hub_is_superspeed(hub->hdev))
-		status = clear_port_feature(hub->hdev, port1,
-						USB_PORT_FEAT_POWER);
+	if (hub_is_superspeed(hub->hdev))
+		status = set_port_feature(hub->hdev,
+				port1 | (USB_SS_PORT_LS_U3 << 3),
+				USB_PORT_FEAT_LINK_STATE);
 	else
 		status = set_port_feature(hub->hdev, port1,
 						USB_PORT_FEAT_SUSPEND);
@@ -2469,8 +2465,13 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 	set_bit(port1, hub->busy_bits);
 
 	/* see 7.1.7.7; affects power usage, but not budgeting */
-	status = clear_port_feature(hub->hdev,
-			port1, USB_PORT_FEAT_SUSPEND);
+	if (hub_is_superspeed(hub->hdev))
+		status = set_port_feature(hub->hdev,
+				port1 | (USB_SS_PORT_LS_U0 << 3),
+				USB_PORT_FEAT_LINK_STATE);
+	else
+		status = clear_port_feature(hub->hdev,
+				port1, USB_PORT_FEAT_SUSPEND);
 	if (status) {
 		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
 				port1, status);
@@ -2492,9 +2493,15 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 
  SuspendCleared:
 	if (status == 0) {
-		if (portchange & USB_PORT_STAT_C_SUSPEND)
-			clear_port_feature(hub->hdev, port1,
-					USB_PORT_FEAT_C_SUSPEND);
+		if (hub_is_superspeed(hub->hdev)) {
+			if (portchange & USB_PORT_STAT_C_LINK_STATE)
+				clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_PORT_LINK_STATE);
+		} else {
+			if (portchange & USB_PORT_STAT_C_SUSPEND)
+				clear_port_feature(hub->hdev, port1,
+						USB_PORT_FEAT_C_SUSPEND);
+		}
 	}
 
 	clear_bit(port1, hub->busy_bits);

drivers/usb/host/xhci-hub.c

@@ -483,7 +483,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			&& (temp & PORT_POWER)
 			&& (bus_state->suspended_ports & (1 << wIndex))) {
 			bus_state->suspended_ports &= ~(1 << wIndex);
-			bus_state->port_c_suspend |= 1 << wIndex;
+			if (hcd->speed != HCD_USB3)
+				bus_state->port_c_suspend |= 1 << wIndex;
 		}
 		if (temp & PORT_CONNECT) {
 			status |= USB_PORT_STAT_CONNECTION;
@@ -656,35 +657,27 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			if (temp & XDEV_U3) {
 				if ((temp & PORT_PE) == 0)
 					goto error;
-				if (DEV_SUPERSPEED(temp)) {
-					temp = xhci_port_state_to_neutral(temp);
-					temp &= ~PORT_PLS_MASK;
-					temp |= PORT_LINK_STROBE | XDEV_U0;
-					xhci_writel(xhci, temp,
-							port_array[wIndex]);
-					xhci_readl(xhci, port_array[wIndex]);
-				} else {
-					temp = xhci_port_state_to_neutral(temp);
-					temp &= ~PORT_PLS_MASK;
-					temp |= PORT_LINK_STROBE | XDEV_RESUME;
-					xhci_writel(xhci, temp,
-							port_array[wIndex]);
 
-					spin_unlock_irqrestore(&xhci->lock,
-							       flags);
-					msleep(20);
-					spin_lock_irqsave(&xhci->lock, flags);
+				temp = xhci_port_state_to_neutral(temp);
+				temp &= ~PORT_PLS_MASK;
+				temp |= PORT_LINK_STROBE | XDEV_RESUME;
+				xhci_writel(xhci, temp,
+						port_array[wIndex]);
 
-					temp = xhci_readl(xhci,
-							port_array[wIndex]);
-					temp = xhci_port_state_to_neutral(temp);
-					temp &= ~PORT_PLS_MASK;
-					temp |= PORT_LINK_STROBE | XDEV_U0;
-					xhci_writel(xhci, temp,
-							port_array[wIndex]);
-				}
-				bus_state->port_c_suspend |= 1 << wIndex;
+				spin_unlock_irqrestore(&xhci->lock,
+						       flags);
+				msleep(20);
+				spin_lock_irqsave(&xhci->lock, flags);
+
+				temp = xhci_readl(xhci,
+						port_array[wIndex]);
+				temp = xhci_port_state_to_neutral(temp);
+				temp &= ~PORT_PLS_MASK;
+				temp |= PORT_LINK_STROBE | XDEV_U0;
+				xhci_writel(xhci, temp,
+						port_array[wIndex]);
 			}
+			bus_state->port_c_suspend |= 1 << wIndex;
 
 			slot_id = xhci_find_slot_id_by_port(hcd, xhci,
 					wIndex + 1);
@@ -755,7 +748,7 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
 	memset(buf, 0, retval);
 	status = 0;
 
-	mask = PORT_CSC | PORT_PEC | PORT_OCC;
+	mask = PORT_CSC | PORT_PEC | PORT_OCC | PORT_PLC;
 
 	spin_lock_irqsave(&xhci->lock, flags);
 	/* For each port, did anything change?  If so, set that bit in buf. */