xhci: Refactor port status into a new function.

The hub control function is *way* too long.  Refactor it into a new
function, and document the side effects of calling that function.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/xhci-hub.c

@@ -534,104 +534,51 @@ void xhci_del_comp_mod_timer(struct xhci_hcd *xhci, u32 status, u16 wIndex)
 	}
 }
 
-int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
-		u16 wIndex, char *buf, u16 wLength)
+/*
+ * Converts a raw xHCI port status into the format that external USB 2.0 or USB
+ * 3.0 hubs use.
+ *
+ * Possible side effects:
+ *  - Mark a port as being done with device resume,
+ *    and ring the endpoint doorbells.
+ *  - Stop the Synopsys redriver Compliance Mode polling.
+ */
+static u32 xhci_get_port_status(struct usb_hcd *hcd,
+		struct xhci_bus_state *bus_state,
+		__le32 __iomem **port_array,
+		u16 wIndex, u32 raw_port_status)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-	int max_ports;
-	unsigned long flags;
-	u32 temp, status;
-	int retval = 0;
-	__le32 __iomem **port_array;
+	u32 status = 0;
 	int slot_id;
-	struct xhci_bus_state *bus_state;
-	u16 link_state = 0;
-	u16 wake_mask = 0;
-	u16 timeout = 0;
-
-	max_ports = xhci_get_ports(hcd, &port_array);
-	bus_state = &xhci->bus_state[hcd_index(hcd)];
-
-	spin_lock_irqsave(&xhci->lock, flags);
-	switch (typeReq) {
-	case GetHubStatus:
-		/* No power source, over-current reported per port */
-		memset(buf, 0, 4);
-		break;
-	case GetHubDescriptor:
-		/* Check to make sure userspace is asking for the USB 3.0 hub
-		 * descriptor for the USB 3.0 roothub.  If not, we stall the
-		 * endpoint, like external hubs do.
-		 */
-		if (hcd->speed == HCD_USB3 &&
-				(wLength < USB_DT_SS_HUB_SIZE ||
-				 wValue != (USB_DT_SS_HUB << 8))) {
-			xhci_dbg(xhci, "Wrong hub descriptor type for "
-					"USB 3.0 roothub.\n");
-			goto error;
-		}
-		xhci_hub_descriptor(hcd, xhci,
-				(struct usb_hub_descriptor *) buf);
-		break;
-	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
-		if ((wValue & 0xff00) != (USB_DT_BOS << 8))
-			goto error;
-
-		if (hcd->speed != HCD_USB3)
-			goto error;
-
-		/* Set the U1 and U2 exit latencies. */
-		memcpy(buf, &usb_bos_descriptor,
-				USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE);
-		temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
-		buf[12] = HCS_U1_LATENCY(temp);
-		put_unaligned_le16(HCS_U2_LATENCY(temp), &buf[13]);
-
-		/* Indicate whether the host has LTM support. */
-		temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
-		if (HCC_LTC(temp))
-			buf[8] |= USB_LTM_SUPPORT;
-
-		spin_unlock_irqrestore(&xhci->lock, flags);
-		return USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;
-	case GetPortStatus:
-		if (!wIndex || wIndex > max_ports)
-			goto error;
-		wIndex--;
-		status = 0;
-		temp = xhci_readl(xhci, port_array[wIndex]);
-		if (temp == 0xffffffff) {
-			retval = -ENODEV;
-			break;
-		}
-		xhci_dbg(xhci, "get port status, actual port %d status  = 0x%x\n", wIndex, temp);
 
 	/* wPortChange bits */
-		if (temp & PORT_CSC)
+	if (raw_port_status & PORT_CSC)
 		status |= USB_PORT_STAT_C_CONNECTION << 16;
-		if (temp & PORT_PEC)
+	if (raw_port_status & PORT_PEC)
 		status |= USB_PORT_STAT_C_ENABLE << 16;
-		if ((temp & PORT_OCC))
+	if ((raw_port_status & PORT_OCC))
 		status |= USB_PORT_STAT_C_OVERCURRENT << 16;
-		if ((temp & PORT_RC))
+	if ((raw_port_status & PORT_RC))
 		status |= USB_PORT_STAT_C_RESET << 16;
 	/* USB3.0 only */
 	if (hcd->speed == HCD_USB3) {
-			if ((temp & PORT_PLC))
+		if ((raw_port_status & PORT_PLC))
 			status |= USB_PORT_STAT_C_LINK_STATE << 16;
-			if ((temp & PORT_WRC))
+		if ((raw_port_status & PORT_WRC))
 			status |= USB_PORT_STAT_C_BH_RESET << 16;
 	}
 
 	if (hcd->speed != HCD_USB3) {
-			if ((temp & PORT_PLS_MASK) == XDEV_U3
-					&& (temp & PORT_POWER))
+		if ((raw_port_status & PORT_PLS_MASK) == XDEV_U3
+				&& (raw_port_status & PORT_POWER))
 			status |= USB_PORT_STAT_SUSPEND;
 	}
-		if ((temp & PORT_PLS_MASK) == XDEV_RESUME &&
-				!DEV_SUPERSPEED(temp)) {
-			if ((temp & PORT_RESET) || !(temp & PORT_PE))
-				goto error;
+	if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME &&
+			!DEV_SUPERSPEED(raw_port_status)) {
+		if ((raw_port_status & PORT_RESET) ||
+				!(raw_port_status & PORT_PE))
+			return 0xffffffff;
 		if (time_after_eq(jiffies,
 					bus_state->resume_done[wIndex])) {
 			xhci_dbg(xhci, "Resume USB2 port %d\n",
@@ -646,7 +593,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 					wIndex + 1);
 			if (!slot_id) {
 				xhci_dbg(xhci, "slot_id is zero\n");
-					goto error;
+				return 0xffffffff;
 			}
 			xhci_ring_device(xhci, slot_id);
 			bus_state->port_c_suspend |= 1 << wIndex;
@@ -661,24 +608,24 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			status |= USB_PORT_STAT_SUSPEND;
 		}
 	}
-		if ((temp & PORT_PLS_MASK) == XDEV_U0
-			&& (temp & PORT_POWER)
+	if ((raw_port_status & PORT_PLS_MASK) == XDEV_U0
+			&& (raw_port_status & PORT_POWER)
 			&& (bus_state->suspended_ports & (1 << wIndex))) {
 		bus_state->suspended_ports &= ~(1 << wIndex);
 		if (hcd->speed != HCD_USB3)
 			bus_state->port_c_suspend |= 1 << wIndex;
 	}
-		if (temp & PORT_CONNECT) {
+	if (raw_port_status & PORT_CONNECT) {
 		status |= USB_PORT_STAT_CONNECTION;
-			status |= xhci_port_speed(temp);
+		status |= xhci_port_speed(raw_port_status);
 	}
-		if (temp & PORT_PE)
+	if (raw_port_status & PORT_PE)
 		status |= USB_PORT_STAT_ENABLE;
-		if (temp & PORT_OC)
+	if (raw_port_status & PORT_OC)
 		status |= USB_PORT_STAT_OVERCURRENT;
-		if (temp & PORT_RESET)
+	if (raw_port_status & PORT_RESET)
 		status |= USB_PORT_STAT_RESET;
-		if (temp & PORT_POWER) {
+	if (raw_port_status & PORT_POWER) {
 		if (hcd->speed == HCD_USB3)
 			status |= USB_SS_PORT_STAT_POWER;
 		else
@@ -686,16 +633,97 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 	}
 	/* Update Port Link State for super speed ports*/
 	if (hcd->speed == HCD_USB3) {
-			xhci_hub_report_link_state(&status, temp);
+		xhci_hub_report_link_state(&status, raw_port_status);
 		/*
 		 * Verify if all USB3 Ports Have entered U0 already.
 		 * Delete Compliance Mode Timer if so.
 		 */
-			xhci_del_comp_mod_timer(xhci, temp, wIndex);
+		xhci_del_comp_mod_timer(xhci, raw_port_status, wIndex);
 	}
 	if (bus_state->port_c_suspend & (1 << wIndex))
 		status |= 1 << USB_PORT_FEAT_C_SUSPEND;
+
+	return status;
+}
+
+int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
+		u16 wIndex, char *buf, u16 wLength)
+{
+	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
+	int max_ports;
+	unsigned long flags;
+	u32 temp, status;
+	int retval = 0;
+	__le32 __iomem **port_array;
+	int slot_id;
+	struct xhci_bus_state *bus_state;
+	u16 link_state = 0;
+	u16 wake_mask = 0;
+	u16 timeout = 0;
+
+	max_ports = xhci_get_ports(hcd, &port_array);
+	bus_state = &xhci->bus_state[hcd_index(hcd)];
+
+	spin_lock_irqsave(&xhci->lock, flags);
+	switch (typeReq) {
+	case GetHubStatus:
+		/* No power source, over-current reported per port */
+		memset(buf, 0, 4);
+		break;
+	case GetHubDescriptor:
+		/* Check to make sure userspace is asking for the USB 3.0 hub
+		 * descriptor for the USB 3.0 roothub.  If not, we stall the
+		 * endpoint, like external hubs do.
+		 */
+		if (hcd->speed == HCD_USB3 &&
+				(wLength < USB_DT_SS_HUB_SIZE ||
+				 wValue != (USB_DT_SS_HUB << 8))) {
+			xhci_dbg(xhci, "Wrong hub descriptor type for "
+					"USB 3.0 roothub.\n");
+			goto error;
+		}
+		xhci_hub_descriptor(hcd, xhci,
+				(struct usb_hub_descriptor *) buf);
+		break;
+	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
+		if ((wValue & 0xff00) != (USB_DT_BOS << 8))
+			goto error;
+
+		if (hcd->speed != HCD_USB3)
+			goto error;
+
+		/* Set the U1 and U2 exit latencies. */
+		memcpy(buf, &usb_bos_descriptor,
+				USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE);
+		temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
+		buf[12] = HCS_U1_LATENCY(temp);
+		put_unaligned_le16(HCS_U2_LATENCY(temp), &buf[13]);
+
+		/* Indicate whether the host has LTM support. */
+		temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
+		if (HCC_LTC(temp))
+			buf[8] |= USB_LTM_SUPPORT;
+
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		return USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;
+	case GetPortStatus:
+		if (!wIndex || wIndex > max_ports)
+			goto error;
+		wIndex--;
+		temp = xhci_readl(xhci, port_array[wIndex]);
+		if (temp == 0xffffffff) {
+			retval = -ENODEV;
+			break;
+		}
+		status = xhci_get_port_status(hcd, bus_state, port_array,
+				wIndex, temp);
+		if (status == 0xffffffff)
+			goto error;
+
+		xhci_dbg(xhci, "get port status, actual port %d status  = 0x%x\n",
+				wIndex, temp);
 		xhci_dbg(xhci, "Get port status returned 0x%x\n", status);
+
 		put_unaligned(cpu_to_le32(status), (__le32 *) buf);
 		break;
 	case SetPortFeature: