usb: dwc2: fix kernel oops during driver probe

This patch make sure that all necessary members of dwc2_hsotg
are initialized before the irq handler is requested. So
the kernel oops triggered by dwc2_handle_common_intr has
been fixed.

  dwc2 20980000.usb: Configuration mismatch. Forcing host mode
  dwc2 20980000.usb: no platform data or transceiver defined
  Unable to handle kernel paging request at virtual address cc860040
  pgd = c0004000
  [cc860040] *pgd=0b41e811, *pte=00000000, *ppte=00000000
  Internal error: Oops: 7 [#1] ARM
  CPU: 0 PID: 1 Comm: swapper Not tainted 4.3.0-rc3+ #19
  Hardware name: BCM2835
  task: cb494000 ti: cb4d0000 task.ti: cb4d0000
  PC is at dwc2_is_controller_alive+0x18/0x34
  LR is at dwc2_handle_common_intr+0x24/0xb60

Acked-by: John Youn <[email protected]>
Tested-by: Marek Szyprowski <[email protected]>
Signed-off-by: Stefan Wahren <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>

Author: lategoodbye

drivers/usb/dwc2/platform.c

@@ -367,20 +367,6 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	if (retval)
 		return retval;
 
-	irq = platform_get_irq(dev, 0);
-	if (irq < 0) {
-		dev_err(&dev->dev, "missing IRQ resource\n");
-		return irq;
-	}
-
-	dev_dbg(hsotg->dev, "registering common handler for irq%d\n",
-		irq);
-	retval = devm_request_irq(hsotg->dev, irq,
-				  dwc2_handle_common_intr, IRQF_SHARED,
-				  dev_name(hsotg->dev), hsotg);
-	if (retval)
-		return retval;
-
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	hsotg->regs = devm_ioremap_resource(&dev->dev, res);
 	if (IS_ERR(hsotg->regs))
@@ -415,6 +401,20 @@ static int dwc2_driver_probe(struct platform_device *dev)
 
 	dwc2_set_all_params(hsotg->core_params, -1);
 
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0) {
+		dev_err(&dev->dev, "missing IRQ resource\n");
+		return irq;
+	}
+
+	dev_dbg(hsotg->dev, "registering common handler for irq%d\n",
+		irq);
+	retval = devm_request_irq(hsotg->dev, irq,
+				  dwc2_handle_common_intr, IRQF_SHARED,
+				  dev_name(hsotg->dev), hsotg);
+	if (retval)
+		return retval;
+
 	retval = dwc2_lowlevel_hw_enable(hsotg);
 	if (retval)
 		return retval;