usb: gadget: udc: fix spin_lock in pch_udc

When remove module g_serial on quark platform, the following Warning on:

Modules linked in: usb_f_acm u_serial g_serial(-) pch_udc libcomposite configfs udc_core
ad7298 industrialio_triggered_buffer kfifo_buf tpm_i2c_infineon indus
CPU: 0 PID: 369 Comm: modprobe Not tainted 3.14.29ltsi-WR7.0.0.0_standard #6
Hardware name: Intel Corp. QUARK/CrossHill, BIOS 0x010100F5 01/01/2014
 f641df0c f641df0c f641dec8 c15ac7fa f641defc c103084f c16c2356 f641df28
 00000171 c16b855c 000009dd c15b2d6f 000009dd c15b2d6f f6bd2000 faae5480
 00000000 f641df14 c10308a3 00000009 f641df0c c16c2356 f641df28 f641df2c
Call Trace:
 [<c15ac7fa>] dump_stack+0x16/0x18
 [<c103084f>] warn_slowpath_common+0x7f/0xa0
 [<c15b2d6f>] ? preempt_count_sub+0x6f/0xc0
 [<c15b2d6f>] ? preempt_count_sub+0x6f/0xc0
 [<c10308a3>] warn_slowpath_fmt+0x33/0x40
 [<c15b2d6f>] preempt_count_sub+0x6f/0xc0
 [<faadbc82>] pch_udc_pcd_pullup+0x32/0xa0 [pch_udc]
 [<fa9747d9>] usb_gadget_remove_driver+0x29/0x60 [udc_core]
 [<fa974869>] usb_gadget_unregister_driver+0x59/0x80 [udc_core]
 [<faa78310>] usb_composite_unregister+0x10/0x20 [libcomposite]
 [<faae50f1>] cleanup+0xd/0xf [g_serial]
 [<c1084c47>] SyS_delete_module+0xf7/0x150
 [<c111f8dd>] ? ____fput+0xd/0x10
 [<c104b2ae>] ? task_work_run+0x6e/0xa0
 [<c15afda5>] syscall_call+0x7/0x7

g_serial module on quark is depended on pch_udc module, ttyGSX cann't recieve
data and warning on when remove g_serial.

It was unlocked before the modification of the structure it was protecting,
fix it as "lock -> unlock" to resolve this.

Signed-off-by: Pengyu Ma <pengyu.ma@windriver.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/udc/pch_udc.c

@@ -620,9 +620,9 @@ static inline void pch_udc_vbus_session(struct pch_udc_dev *dev,
 		dev->vbus_session = 1;
 	} else {
 		if (dev->driver && dev->driver->disconnect) {
-			spin_unlock(&dev->lock);
-			dev->driver->disconnect(&dev->gadget);
 			spin_lock(&dev->lock);
+			dev->driver->disconnect(&dev->gadget);
+			spin_unlock(&dev->lock);
 		}
 		pch_udc_set_disconnect(dev);
 		dev->vbus_session = 0;
@@ -1191,9 +1191,9 @@ static int pch_udc_pcd_pullup(struct usb_gadget *gadget, int is_on)
 		pch_udc_reconnect(dev);
 	} else {
 		if (dev->driver && dev->driver->disconnect) {
-			spin_unlock(&dev->lock);
-			dev->driver->disconnect(&dev->gadget);
 			spin_lock(&dev->lock);
+			dev->driver->disconnect(&dev->gadget);
+			spin_unlock(&dev->lock);
 		}
 		pch_udc_set_disconnect(dev);
 	}
@@ -1488,11 +1488,11 @@ static void complete_req(struct pch_udc_ep *ep, struct pch_udc_request *req,
 		req->dma_mapped = 0;
 	}
 	ep->halted = 1;
-	spin_unlock(&dev->lock);
+	spin_lock(&dev->lock);
 	if (!ep->in)
 		pch_udc_ep_clear_rrdy(ep);
 	usb_gadget_giveback_request(&ep->ep, &req->req);
-	spin_lock(&dev->lock);
+	spin_unlock(&dev->lock);
 	ep->halted = halted;
 }
 
@@ -2414,7 +2414,7 @@ static void pch_udc_svc_control_out(struct pch_udc_dev *dev)
 			dev->gadget.ep0 = &dev->ep[UDC_EP0IN_IDX].ep;
 		else /* OUT */
 			dev->gadget.ep0 = &ep->ep;
-		spin_unlock(&dev->lock);
+		spin_lock(&dev->lock);
 		/* If Mass storage Reset */
 		if ((dev->setup_data.bRequestType == 0x21) &&
 		    (dev->setup_data.bRequest == 0xFF))
@@ -2422,7 +2422,7 @@ static void pch_udc_svc_control_out(struct pch_udc_dev *dev)
 		/* call gadget with setup data received */
 		setup_supported = dev->driver->setup(&dev->gadget,
 						     &dev->setup_data);
-		spin_lock(&dev->lock);
+		spin_unlock(&dev->lock);
 
 		if (dev->setup_data.bRequestType & USB_DIR_IN) {
 			ep->td_data->status = (ep->td_data->status &
@@ -2594,9 +2594,9 @@ static void pch_udc_svc_ur_interrupt(struct pch_udc_dev *dev)
 		empty_req_queue(ep);
 	}
 	if (dev->driver) {
-		spin_unlock(&dev->lock);
-		usb_gadget_udc_reset(&dev->gadget, dev->driver);
 		spin_lock(&dev->lock);
+		usb_gadget_udc_reset(&dev->gadget, dev->driver);
+		spin_unlock(&dev->lock);
 	}
 }
 
@@ -2675,9 +2675,9 @@ static void pch_udc_svc_intf_interrupt(struct pch_udc_dev *dev)
 		dev->ep[i].halted = 0;
 	}
 	dev->stall = 0;
-	spin_unlock(&dev->lock);
-	ret = dev->driver->setup(&dev->gadget, &dev->setup_data);
 	spin_lock(&dev->lock);
+	ret = dev->driver->setup(&dev->gadget, &dev->setup_data);
+	spin_unlock(&dev->lock);
 }
 
 /**
@@ -2712,9 +2712,9 @@ static void pch_udc_svc_cfg_interrupt(struct pch_udc_dev *dev)
 	dev->stall = 0;
 
 	/* call gadget zero with setup data received */
-	spin_unlock(&dev->lock);
-	ret = dev->driver->setup(&dev->gadget, &dev->setup_data);
 	spin_lock(&dev->lock);
+	ret = dev->driver->setup(&dev->gadget, &dev->setup_data);
+	spin_unlock(&dev->lock);
 }
 
 /**
@@ -2747,18 +2747,18 @@ static void pch_udc_dev_isr(struct pch_udc_dev *dev, u32 dev_intr)
 	if (dev_intr & UDC_DEVINT_US) {
 		if (dev->driver
 			&& dev->driver->suspend) {
-			spin_unlock(&dev->lock);
-			dev->driver->suspend(&dev->gadget);
 			spin_lock(&dev->lock);
+			dev->driver->suspend(&dev->gadget);
+			spin_unlock(&dev->lock);
 		}
 
 		vbus = pch_vbus_gpio_get_value(dev);
 		if ((dev->vbus_session == 0)
 			&& (vbus != 1)) {
 			if (dev->driver && dev->driver->disconnect) {
-				spin_unlock(&dev->lock);
-				dev->driver->disconnect(&dev->gadget);
 				spin_lock(&dev->lock);
+				dev->driver->disconnect(&dev->gadget);
+				spin_unlock(&dev->lock);
 			}
 			pch_udc_reconnect(dev);
 		} else if ((dev->vbus_session == 0)