usb: dwc3: Don't reinitialize core during host bus-suspend/resume

Driver powers-off PHYs and reinitializes DWC3 core and gadget on
resume. While this works fine for gadget mode but in host
mode there is not re-initialization of host stack. Also, resetting
bus as part of bus_suspend/resume is not correct which could affect
(or disconnect) connected devices.
Fix this by not reinitializing core on suspend/resume in host mode
for HOST only and OTG/drd configurations.
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.c

@@ -927,6 +927,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
+		dwc->current_dr_role = DWC3_GCTL_PRTCAP_DEVICE;
 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 
 		if (dwc->usb2_phy)
@@ -942,6 +943,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 		}
 		break;
 	case USB_DR_MODE_HOST:
+		dwc->current_dr_role = DWC3_GCTL_PRTCAP_HOST;
 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
 
 		if (dwc->usb2_phy)
@@ -1293,21 +1295,19 @@ static int dwc3_suspend_common(struct dwc3 *dwc)
 {
 	unsigned long	flags;
 
-	switch (dwc->dr_mode) {
-	case USB_DR_MODE_PERIPHERAL:
-	case USB_DR_MODE_OTG:
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_DEVICE:
 		spin_lock_irqsave(&dwc->lock, flags);
 		dwc3_gadget_suspend(dwc);
 		spin_unlock_irqrestore(&dwc->lock, flags);
+		dwc3_core_exit(dwc);
 		break;
-	case USB_DR_MODE_HOST:
+	case DWC3_GCTL_PRTCAP_HOST:
 	default:
 		/* do nothing */
 		break;
 	}
 
-	dwc3_core_exit(dwc);
-
 	return 0;
 }
 
@@ -1316,18 +1316,17 @@ static int dwc3_resume_common(struct dwc3 *dwc)
 	unsigned long	flags;
 	int		ret;
 
-	ret = dwc3_core_init(dwc);
-	if (ret)
-		return ret;
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_DEVICE:
+		ret = dwc3_core_init(dwc);
+		if (ret)
+			return ret;
 
-	switch (dwc->dr_mode) {
-	case USB_DR_MODE_PERIPHERAL:
-	case USB_DR_MODE_OTG:
 		spin_lock_irqsave(&dwc->lock, flags);
 		dwc3_gadget_resume(dwc);
 		spin_unlock_irqrestore(&dwc->lock, flags);
-		/* FALLTHROUGH */
-	case USB_DR_MODE_HOST:
+		break;
+	case DWC3_GCTL_PRTCAP_HOST:
 	default:
 		/* do nothing */
 		break;
@@ -1338,7 +1337,7 @@ static int dwc3_resume_common(struct dwc3 *dwc)
 
 static int dwc3_runtime_checks(struct dwc3 *dwc)
 {
-	switch (dwc->dr_mode) {
+	switch (dwc->current_dr_role) {
 	case USB_DR_MODE_PERIPHERAL:
 	case USB_DR_MODE_OTG:
 		if (dwc->connected)
@@ -1381,12 +1380,11 @@ static int dwc3_runtime_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	switch (dwc->dr_mode) {
-	case USB_DR_MODE_PERIPHERAL:
-	case USB_DR_MODE_OTG:
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_DEVICE:
 		dwc3_gadget_process_pending_events(dwc);
 		break;
-	case USB_DR_MODE_HOST:
+	case DWC3_GCTL_PRTCAP_HOST:
 	default:
 		/* do nothing */
 		break;
@@ -1402,13 +1400,12 @@ static int dwc3_runtime_idle(struct device *dev)
 {
 	struct dwc3     *dwc = dev_get_drvdata(dev);
 
-	switch (dwc->dr_mode) {
-	case USB_DR_MODE_PERIPHERAL:
-	case USB_DR_MODE_OTG:
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_DEVICE:
 		if (dwc3_runtime_checks(dwc))
 			return -EBUSY;
 		break;
-	case USB_DR_MODE_HOST:
+	case DWC3_GCTL_PRTCAP_HOST:
 	default:
 		/* do nothing */
 		break;