USB/host: Bugfix: Return length of copied buffer in uhci_hub_control()

In addition to the error statuses -ETIMEDOUT and -EPIPE, uhci_hub_control()
needs to return the length of copied buffer when appropriate, so that the
returned status of ->hub_control() in rh_call_control() in the USB core
HCD can be properly handled.

This patch also removes the OK() macro to make the code more readable.
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/uhci-hub.c

@@ -75,8 +75,6 @@ static inline int get_hub_status_data(struct uhci_hcd *uhci, char *buf)
 	return !!*buf;
 }
 
-#define OK(x)			len = (x); break
-
 #define CLR_RH_PORTSTAT(x) \
 	status = uhci_readw(uhci, port_addr);	\
 	status &= ~(RWC_BITS|WZ_BITS); \
@@ -244,7 +242,7 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			u16 wIndex, char *buf, u16 wLength)
 {
 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
-	int status, lstatus, retval = 0, len = 0;
+	int status, lstatus, retval = 0;
 	unsigned int port = wIndex - 1;
 	unsigned long port_addr = USBPORTSC1 + 2 * port;
 	u16 wPortChange, wPortStatus;
@@ -258,7 +256,8 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 	case GetHubStatus:
 		*(__le32 *)buf = cpu_to_le32(0);
-		OK(4);		/* hub power */
+		retval = 4; /* hub power */
+		break;
 	case GetPortStatus:
 		if (port >= uhci->rh_numports)
 			goto err;
@@ -311,13 +310,14 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 		*(__le16 *)buf = cpu_to_le16(wPortStatus);
 		*(__le16 *)(buf + 2) = cpu_to_le16(wPortChange);
-		OK(4);
+		retval = 4;
+		break;
 	case SetHubFeature:		/* We don't implement these */
 	case ClearHubFeature:
 		switch (wValue) {
 		case C_HUB_OVER_CURRENT:
 		case C_HUB_LOCAL_POWER:
-			OK(0);
+			break;
 		default:
 			goto err;
 		}
@@ -329,7 +329,7 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		switch (wValue) {
 		case USB_PORT_FEAT_SUSPEND:
 			SET_RH_PORTSTAT(USBPORTSC_SUSP);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_RESET:
 			SET_RH_PORTSTAT(USBPORTSC_PR);
 
@@ -338,10 +338,10 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 			/* USB v2.0 7.1.7.5 */
 			uhci->ports_timeout = jiffies + msecs_to_jiffies(50);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_POWER:
 			/* UHCI has no power switching */
-			OK(0);
+			break;
 		default:
 			goto err;
 		}
@@ -356,10 +356,10 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 			/* Disable terminates Resume signalling */
 			uhci_finish_suspend(uhci, port, port_addr);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_C_ENABLE:
 			CLR_RH_PORTSTAT(USBPORTSC_PEC);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_SUSPEND:
 			if (!(uhci_readw(uhci, port_addr) & USBPORTSC_SUSP)) {
 
@@ -382,32 +382,32 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 					uhci->ports_timeout = jiffies +
 						msecs_to_jiffies(20);
 			}
-			OK(0);
+			break;
 		case USB_PORT_FEAT_C_SUSPEND:
 			clear_bit(port, &uhci->port_c_suspend);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_POWER:
 			/* UHCI has no power switching */
 			goto err;
 		case USB_PORT_FEAT_C_CONNECTION:
 			CLR_RH_PORTSTAT(USBPORTSC_CSC);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_C_OVER_CURRENT:
 			CLR_RH_PORTSTAT(USBPORTSC_OCC);
-			OK(0);
+			break;
 		case USB_PORT_FEAT_C_RESET:
 			/* this driver won't report these */
-			OK(0);
+			break;
 		default:
 			goto err;
 		}
 		break;
 	case GetHubDescriptor:
-		len = min_t(unsigned int, sizeof(root_hub_hub_des), wLength);
-		memcpy(buf, root_hub_hub_des, len);
-		if (len > 2)
+		retval = min_t(unsigned int, sizeof(root_hub_hub_des), wLength);
+		memcpy(buf, root_hub_hub_des, retval);
+		if (retval > 2)
 			buf[2] = uhci->rh_numports;
-		OK(len);
+		break;
 	default:
 err:
 		retval = -EPIPE;