usb: dwc2: Allow exiting hibernation from gpwrdn rst detect

When device cable is disconnected core receives suspend
interrupt and enters hibernation. After entering
into hibernation GPWRDN_RST_DET and GPWRDN_STS_CHGINT
interrupts are asserted.

Allowed exit from gadget hibernation from
GPWRDN_RST_DET by checking only linestate.

Changed the return type of "dwc2_handle_gpwrdn_intr()"
function from void to int because exit from hibernation
functions have a return value.
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210416124723.B6F17A005C@mailhost.synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/core_intr.c

@@ -751,10 +751,11 @@ static inline void dwc_handle_gpwrdn_disc_det(struct dwc2_hsotg *hsotg,
  * The GPWRDN interrupts are those that occur in both Host and
  * Device mode while core is in hibernated state.
  */
-static void dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
+static int dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 gpwrdn;
 	int linestate;
+	int ret = 0;
 
 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
 	/* clear all interrupt */
@@ -778,17 +779,27 @@ static void dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
 		if (hsotg->hw_params.hibernation &&
 		    hsotg->hibernated) {
 			if (gpwrdn & GPWRDN_IDSTS) {
-				dwc2_exit_hibernation(hsotg, 0, 0, 0);
+				ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
+				if (ret)
+					dev_err(hsotg->dev,
+						"exit hibernation failed.\n");
 				call_gadget(hsotg, resume);
 			} else {
-				dwc2_exit_hibernation(hsotg, 1, 0, 1);
+				ret = dwc2_exit_hibernation(hsotg, 1, 0, 1);
+				if (ret)
+					dev_err(hsotg->dev,
+						"exit hibernation failed.\n");
 			}
 		}
 	} else if ((gpwrdn & GPWRDN_RST_DET) &&
 		   (gpwrdn & GPWRDN_RST_DET_MSK)) {
 		dev_dbg(hsotg->dev, "%s: GPWRDN_RST_DET\n", __func__);
-		if (!linestate && (gpwrdn & GPWRDN_BSESSVLD))
-			dwc2_exit_hibernation(hsotg, 0, 1, 0);
+		if (!linestate) {
+			ret = dwc2_exit_hibernation(hsotg, 0, 1, 0);
+			if (ret)
+				dev_err(hsotg->dev,
+					"exit hibernation failed.\n");
+		}
 	} else if ((gpwrdn & GPWRDN_STS_CHGINT) &&
 		   (gpwrdn & GPWRDN_STS_CHGINT_MSK)) {
 		dev_dbg(hsotg->dev, "%s: GPWRDN_STS_CHGINT\n", __func__);
@@ -800,6 +811,8 @@ static void dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
 		 */
 		dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
 	}
+
+	return ret;
 }
 
 /*