From 9e95a66cce7250c358d496e1c3b62e29ce79ef40 Mon Sep 17 00:00:00 2001
From: Minas Harutyunyan <hminas@synopsys.com>
Date: Tue, 16 Jan 2018 16:03:58 +0400
Subject: [PATCH] usb: dwc2: Add safety check for STSPHSERCVD intr

STSPHSERCVD (status phase received) interrupt should be
handled when EP0 is in DWC2_EP0_DATA_OUT state.

Sometimes STSPHSERCVD interrupt asserted , when EP0
is not in DATA_OUT state. Spurios interrupt.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
---
 drivers/usb/dwc2/gadget.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 57c7400057fa..d6222e946463 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2976,9 +2976,13 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
 	if (ints & DXEPINT_STSPHSERCVD) {
 		dev_dbg(hsotg->dev, "%s: StsPhseRcvd\n", __func__);
 
-		/* Move to STATUS IN for DDMA */
-		if (using_desc_dma(hsotg))
-			dwc2_hsotg_ep0_zlp(hsotg, true);
+		/* Safety check EP0 state when STSPHSERCVD asserted */
+		if (hsotg->ep0_state == DWC2_EP0_DATA_OUT) {
+			/* Move to STATUS IN for DDMA */
+			if (using_desc_dma(hsotg))
+				dwc2_hsotg_ep0_zlp(hsotg, true);
+		}
+
 	}
 
 	if (ints & DXEPINT_BACK2BACKSETUP)
-- 
2.30.9