From 281a94362bbe32c020027a7d6facb37f39723672 Mon Sep 17 00:00:00 2001
From: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Date: Tue, 20 Jul 2021 05:41:24 -0700
Subject: [PATCH] usb: dwc2: gadget: Fix sending zero length packet in DDMA
 mode.

commit d53dc38857f6dbefabd9eecfcbf67b6eac9a1ef4 upstream.

Sending zero length packet in DDMA mode perform by DMA descriptor
by setting SP (short packet) flag.

For DDMA in function dwc2_hsotg_complete_in() does not need to send
zlp.

Tested by USBCV MSC tests.

Fixes: f71b5e2533de ("usb: dwc2: gadget: fix zero length packet transfers")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Link: https://lore.kernel.org/r/967bad78c55dd2db1c19714eee3d0a17cf99d74a.1626777738.git.Minas.Harutyunyan@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/dwc2/gadget.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 566bc1e604af4..66dfcdbd1e03a 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2748,12 +2748,14 @@ static void dwc2_hsotg_complete_in(struct dwc2_hsotg *hsotg,
 		return;
 	}
 
-	/* Zlp for all endpoints, for ep0 only in DATA IN stage */
+	/* Zlp for all endpoints in non DDMA, for ep0 only in DATA IN stage */
 	if (hs_ep->send_zlp) {
-		dwc2_hsotg_program_zlp(hsotg, hs_ep);
 		hs_ep->send_zlp = 0;
-		/* transfer will be completed on next complete interrupt */
-		return;
+		if (!using_desc_dma(hsotg)) {
+			dwc2_hsotg_program_zlp(hsotg, hs_ep);
+			/* transfer will be completed on next complete interrupt */
+			return;
+		}
 	}
 
 	if (hs_ep->index == 0 && hsotg->ep0_state == DWC2_EP0_DATA_IN) {
-- 
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