staging: vt6656: Fix URB submitted while active warning.

This error happens because PIPEnsControlOut and PIPEnsControlIn unlock the
spin lock for delay, letting in another thread.

The patch moves the current MP_SET_FLAG to before filling
of sUsbCtlRequest for pControlURB and clears it in event of failing.

Any thread calling either function while fMP_CONTROL_READS or fMP_CONTROL_WRITES
flags set will return STATUS_FAILURE.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Cc: stable@vger.kernel.org # 3.8
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/usbpipe.c

@@ -126,6 +126,11 @@ int PIPEnsControlOut(struct vnt_private *pDevice, u8 byRequest, u16 wValue,
     if (pDevice->Flags & fMP_CONTROL_WRITES)
         return STATUS_FAILURE;
 
+	if (pDevice->Flags & fMP_CONTROL_READS)
+		return STATUS_FAILURE;
+
+	MP_SET_FLAG(pDevice, fMP_CONTROL_WRITES);
+
 	pDevice->sUsbCtlRequest.bRequestType = 0x40;
 	pDevice->sUsbCtlRequest.bRequest = byRequest;
 	pDevice->sUsbCtlRequest.wValue = cpu_to_le16p(&wValue);
@@ -140,12 +145,13 @@ int PIPEnsControlOut(struct vnt_private *pDevice, u8 byRequest, u16 wValue,
 
 	ntStatus = usb_submit_urb(pDevice->pControlURB, GFP_ATOMIC);
 	if (ntStatus != 0) {
-		DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"control send request submission failed: %d\n", ntStatus);
+		DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO
+			"control send request submission failed: %d\n",
+				ntStatus);
+		MP_CLEAR_FLAG(pDevice, fMP_CONTROL_WRITES);
 		return STATUS_FAILURE;
 	}
-	else {
-	    MP_SET_FLAG(pDevice, fMP_CONTROL_WRITES);
-	}
+
 	spin_unlock_irq(&pDevice->lock);
     for (ii = 0; ii <= USB_CTL_WAIT; ii ++) {
 
@@ -179,6 +185,11 @@ int PIPEnsControlIn(struct vnt_private *pDevice, u8 byRequest, u16 wValue,
     if (pDevice->Flags & fMP_CONTROL_READS)
 	return STATUS_FAILURE;
 
+	if (pDevice->Flags & fMP_CONTROL_WRITES)
+		return STATUS_FAILURE;
+
+	MP_SET_FLAG(pDevice, fMP_CONTROL_READS);
+
 	pDevice->sUsbCtlRequest.bRequestType = 0xC0;
 	pDevice->sUsbCtlRequest.bRequest = byRequest;
 	pDevice->sUsbCtlRequest.wValue = cpu_to_le16p(&wValue);
@@ -192,10 +203,11 @@ int PIPEnsControlIn(struct vnt_private *pDevice, u8 byRequest, u16 wValue,
 
 	ntStatus = usb_submit_urb(pDevice->pControlURB, GFP_ATOMIC);
 	if (ntStatus != 0) {
-		DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"control request submission failed: %d\n", ntStatus);
-	}else {
-		MP_SET_FLAG(pDevice, fMP_CONTROL_READS);
-    }
+		DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO
+			"control request submission failed: %d\n", ntStatus);
+		MP_CLEAR_FLAG(pDevice, fMP_CONTROL_READS);
+		return STATUS_FAILURE;
+	}
 
 	spin_unlock_irq(&pDevice->lock);
     for (ii = 0; ii <= USB_CTL_WAIT; ii ++) {