[PATCH v3] usb: dwc2: gadget: Fix sending zero length packet in DDMA mode.

* [PATCH v3] usb: dwc2: gadget: Fix sending zero length packet in DDMA mode.
@ 2021-07-12 11:05 Minas Harutyunyan
  0 siblings, 0 replies; only message in thread
From: Minas Harutyunyan @ 2021-07-12 11:05 UTC (permalink / raw)
  To: Felipe Balbi, Greg Kroah-Hartman, Minas Harutyunyan,
	Paul Zimmerman, linux-usb, Mian Yousaf Kaukab, Gregory Herrero
  Cc: John Youn, Minas Harutyunyan, Robert Baldyga

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")
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
---
 Changes in v3:
 - Updated mail recipient list
 Changes in v2:
 - Minor typo correction in comments

 drivers/usb/dwc2/gadget.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index c581ee41ac81..bf456b4e191f 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2749,9 +2749,11 @@ 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);
+		if (!using_desc_dma(hsotg))
+			dwc2_hsotg_program_zlp(hsotg, hs_ep);
+
 		hs_ep->send_zlp = 0;
 		/* transfer will be completed on next complete interrupt */
 		return;

base-commit: 89c222503a5bda476be00a2668abd7ea435e1cfa
-- 
2.11.0


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