xhci: Rename variables and reduce register reads.

The xhci_bus_suspend() and xhci_bus_resume() functions are a bit hard to
read, because they have an ambiguously named variable "port".  Rename it
to "port_index".  Introduce a new temporary variable, "max_ports" that
holds the maximum number of roothub ports the host controller supports.
This will reduce the number of register reads, and make it easy to change
the maximum number of ports when there are two roothubs.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/xhci-hub.c

@@ -568,42 +568,44 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
 int xhci_bus_suspend(struct usb_hcd *hcd)
 {
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
-	int port;
+	int max_ports, port_index;
 	unsigned long flags;
 
 	xhci_dbg(xhci, "suspend root hub\n");
+	max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
 
 	spin_lock_irqsave(&xhci->lock, flags);
 
 	if (hcd->self.root_hub->do_remote_wakeup) {
-		port = HCS_MAX_PORTS(xhci->hcs_params1);
-		while (port--) {
-			if (xhci->resume_done[port] != 0) {
+		port_index = max_ports;
+		while (port_index--) {
+			if (xhci->resume_done[port_index] != 0) {
 				spin_unlock_irqrestore(&xhci->lock, flags);
 				xhci_dbg(xhci, "suspend failed because "
 						"port %d is resuming\n",
-						port + 1);
+						port_index + 1);
 				return -EBUSY;
 			}
 		}
 	}
 
-	port = HCS_MAX_PORTS(xhci->hcs_params1);
+	port_index = max_ports;
 	xhci->bus_suspended = 0;
-	while (port--) {
+	while (port_index--) {
 		/* suspend the port if the port is not suspended */
 		u32 __iomem *addr;
 		u32 t1, t2;
 		int slot_id;
 
 		addr = &xhci->op_regs->port_status_base +
-			NUM_PORT_REGS * (port & 0xff);
+			NUM_PORT_REGS * (port_index & 0xff);
 		t1 = xhci_readl(xhci, addr);
 		t2 = xhci_port_state_to_neutral(t1);
 
 		if ((t1 & PORT_PE) && !(t1 & PORT_PLS_MASK)) {
-			xhci_dbg(xhci, "port %d not suspended\n", port);
-			slot_id = xhci_find_slot_id_by_port(xhci, port + 1);
+			xhci_dbg(xhci, "port %d not suspended\n", port_index);
+			slot_id = xhci_find_slot_id_by_port(xhci,
+					port_index + 1);
 			if (slot_id) {
 				spin_unlock_irqrestore(&xhci->lock, flags);
 				xhci_stop_device(xhci, slot_id, 1);
@@ -611,7 +613,7 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 			}
 			t2 &= ~PORT_PLS_MASK;
 			t2 |= PORT_LINK_STROBE | XDEV_U3;
-			set_bit(port, &xhci->bus_suspended);
+			set_bit(port_index, &xhci->bus_suspended);
 		}
 		if (hcd->self.root_hub->do_remote_wakeup) {
 			if (t1 & PORT_CONNECT) {
@@ -634,7 +636,7 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 			u32 tmp;
 
 			addr = &xhci->op_regs->port_power_base +
-				NUM_PORT_REGS * (port & 0xff);
+				NUM_PORT_REGS * (port_index & 0xff);
 			tmp = xhci_readl(xhci, addr);
 			tmp |= PORT_RWE;
 			xhci_writel(xhci, tmp, addr);
@@ -649,11 +651,12 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 int xhci_bus_resume(struct usb_hcd *hcd)
 {
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
-	int port;
+	int max_ports, port_index;
 	u32 temp;
 	unsigned long flags;
 
 	xhci_dbg(xhci, "resume root hub\n");
+	max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
 
 	if (time_before(jiffies, xhci->next_statechange))
 		msleep(5);
@@ -669,8 +672,8 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 	temp &= ~CMD_EIE;
 	xhci_writel(xhci, temp, &xhci->op_regs->command);
 
-	port = HCS_MAX_PORTS(xhci->hcs_params1);
-	while (port--) {
+	port_index = max_ports;
+	while (port_index--) {
 		/* Check whether need resume ports. If needed
 		   resume port and disable remote wakeup */
 		u32 __iomem *addr;
@@ -678,13 +681,13 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 		int slot_id;
 
 		addr = &xhci->op_regs->port_status_base +
-			NUM_PORT_REGS * (port & 0xff);
+			NUM_PORT_REGS * (port_index & 0xff);
 		temp = xhci_readl(xhci, addr);
 		if (DEV_SUPERSPEED(temp))
 			temp &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
 		else
 			temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
-		if (test_bit(port, &xhci->bus_suspended) &&
+		if (test_bit(port_index, &xhci->bus_suspended) &&
 		    (temp & PORT_PLS_MASK)) {
 			if (DEV_SUPERSPEED(temp)) {
 				temp = xhci_port_state_to_neutral(temp);
@@ -707,7 +710,7 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 				temp |= PORT_LINK_STROBE | XDEV_U0;
 				xhci_writel(xhci, temp, addr);
 			}
-			slot_id = xhci_find_slot_id_by_port(xhci, port + 1);
+			slot_id = xhci_find_slot_id_by_port(xhci, port_index + 1);
 			if (slot_id)
 				xhci_ring_device(xhci, slot_id);
 		} else
@@ -719,7 +722,7 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 			u32 tmp;
 
 			addr = &xhci->op_regs->port_power_base +
-				NUM_PORT_REGS * (port & 0xff);
+				NUM_PORT_REGS * (port_index & 0xff);
 			tmp = xhci_readl(xhci, addr);
 			tmp &= ~PORT_RWE;
 			xhci_writel(xhci, tmp, addr);

drivers/usb/host/xhci-ring.c

@@ -1163,7 +1163,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
 	u32 port_id;
 	u32 temp, temp1;
 	u32 __iomem *addr;
-	int ports;
+	int max_ports;
 	int slot_id;
 
 	/* Port status change events always have a successful completion code */
@@ -1174,8 +1174,8 @@ static void handle_port_status(struct xhci_hcd *xhci,
 	port_id = GET_PORT_ID(event->generic.field[0]);
 	xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
 
-	ports = HCS_MAX_PORTS(xhci->hcs_params1);
-	if ((port_id <= 0) || (port_id > ports)) {
+	max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
+	if ((port_id <= 0) || (port_id > max_ports)) {
 		xhci_warn(xhci, "Invalid port id %d\n", port_id);
 		goto cleanup;
 	}