diff mbox series

[5.8,232/255] usb: dwc3: gadget: Fix handling ZLP

Message ID 20200901151011.866295207@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH Sept. 1, 2020, 3:11 p.m. UTC 
From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

commit d2ee3ff79e6a3d4105e684021017d100524dc560 upstream.

The usb_request->zero doesn't apply for isoc. Also, if we prepare a
0-length (ZLP) TRB for the OUT direction, we need to prepare an extra
TRB to pad up to the MPS alignment. Use the same bounce buffer for the
ZLP TRB and the extra pad TRB.

Cc: <stable@vger.kernel.org> # v4.5+
Fixes: d6e5a549cc4d ("usb: dwc3: simplify ZLP handling")
Fixes: 04c03d10e507 ("usb: dwc3: gadget: handle request->zero")
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/dwc3/gadget.c |   25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1199,6 +1199,7 @@  static void dwc3_prepare_one_trb_linear(
 				req->request.no_interrupt,
 				req->request.is_last);
 	} else if (req->request.zero && req->request.length &&
+		   !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
 		   (IS_ALIGNED(req->request.length, maxp))) {
 		struct dwc3	*dwc = dep->dwc;
 		struct dwc3_trb	*trb;
@@ -1208,14 +1209,25 @@  static void dwc3_prepare_one_trb_linear(
 		/* prepare normal TRB */
 		dwc3_prepare_one_trb(dep, req, length, true, 0);
 
-		/* Now prepare one extra TRB to handle ZLP */
+		/* Prepare one extra TRB to handle ZLP */
 		trb = &dep->trb_pool[dep->trb_enqueue];
 		req->num_trbs++;
 		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
-				false, 1, req->request.stream_id,
+				!req->direction, 1, req->request.stream_id,
 				req->request.short_not_ok,
 				req->request.no_interrupt,
 				req->request.is_last);
+
+		/* Prepare one more TRB to handle MPS alignment for OUT */
+		if (!req->direction) {
+			trb = &dep->trb_pool[dep->trb_enqueue];
+			req->num_trbs++;
+			__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,
+					       false, 1, req->request.stream_id,
+					       req->request.short_not_ok,
+					       req->request.no_interrupt,
+					       req->request.is_last);
+		}
 	} else {
 		dwc3_prepare_one_trb(dep, req, length, false, 0);
 	}
@@ -2668,8 +2680,17 @@  static int dwc3_gadget_ep_cleanup_comple
 				status);
 
 	if (req->needs_extra_trb) {
+		unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
+
 		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
 				status);
+
+		/* Reclaim MPS padding TRB for ZLP */
+		if (!req->direction && req->request.zero && req->request.length &&
+		    !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
+		    (IS_ALIGNED(req->request.length, maxp)))
+			ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event, status);
+
 		req->needs_extra_trb = false;
 	}