usb: dwc2: Add exit clock gating from session request interrupt

Added clock gating exit flow from session
request interrupt handler according programming guide.
Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210413073638.921E8A0099@mailhost.synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/core_intr.c

@@ -316,7 +316,8 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
 		hsotg->lx_state);
 
 	if (dwc2_is_device_mode(hsotg)) {
-		if (hsotg->lx_state == DWC2_L2 && hsotg->in_ppd) {
+		if (hsotg->lx_state == DWC2_L2) {
+			if (hsotg->in_ppd) {
 				ret = dwc2_exit_partial_power_down(hsotg, 0,
 								   true);
 				if (ret)
@@ -324,6 +325,12 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
 						"exit power_down failed\n");
 			}
 
+			/* Exit gadget mode clock gating. */
+			if (hsotg->params.power_down ==
+			    DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended)
+				dwc2_gadget_exit_clock_gating(hsotg, 0);
+		}
+
 		/*
 		 * Report disconnect if there is any previous session
 		 * established