usb: dwc3: gadget: Set maxpacket size for ep0 IN

Hi,

Quoted 28 lines · Felipe Balbi

Hi,

Quoted 24 lines · Thinh Nguyen

There are 2 control endpoint structures for DWC3. However, the driver only updates the OUT direction control endpoint structure during ConnectDone event. DWC3 driver needs to update the endpoint max packet size for control IN endpoint as well. If the max packet size is not properly set, then the driver will incorrectly calculate the data transfer size and fail to send ZLP for HS/FS 3-stage control read transfer.

The fix is simply to update the max packet size for the ep0 IN direction during ConnectDone event.

Signed-off-by Thinh Nguyen <[email protected]>

---
  drivers/usb/dwc3/gadget.c | 2 ++
  1 file changed, 2 insertions(+)

drivers/usb/dwc3/gadget.c +0 -0

index bdf2a2014ebd..6ae924d95cbc 100644
@@ -2751,6 +2751,8 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
  		break;
  	}
 

Quoted 6 lines

drivers/usb/dwc3/gadget.c static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc) · line 2754

Quoted 1 line

drivers/usb/dwc3/gadget.c +1 -0

+	dwc->eps[1]->endpoint.maxpacket = dwc->gadget.ep0->maxpacket;

thanks :-) I've had that on my list for a while but never got to it since it has no real effects other than reporting properly on tracepoints :-)

Just to clarify, this is a bug. We found this issue when we test for HS/FS 3-stage control read transfer for ZLP.