The current implementation for ZLP handling of usb_request->zero for ep0
is only for control IN requests. For OUT direction, DWC3 needs to check
and set up for MPS boundary alignment, and it doesn't do that at the
moment.
Usually, control OUT requests can indicate its transfer size via the
wLength field of the control message. So usb_request->zero is usually
not needed for OUT direction. To handle ZLP OUT for control endpoint,
we'd need to allocate at least 3 TRBs for control requests (we have 2 at
the moment). For now, let's just make sure the current ZLP setup is only
for IN direction.
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
---
drivers/usb/dwc3/ep0.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 59f2e8c31bd1..ade9503cf876 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -979,7 +979,7 @@ static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
false);
ret = dwc3_ep0_start_trans(dep);
} else if (IS_ALIGNED(req->request.length, dep->endpoint.maxpacket) &&
- req->request.length && req->request.zero) {
+ req->request.length && req->request.zero && req->direction) {
ret = usb_gadget_map_request_by_dev(dwc->sysdev,
&req->request, dep->number);
--
2.28.0
