Hi, Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes: > Hi, > > On 1/8/2018 4:06 AM, Felipe Balbi wrote: >> >> Hi, >> >> Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes: >>> 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 <thinhn@xxxxxxxxxxxx> >>> --- >>> drivers/usb/dwc3/gadget.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c >>> index bdf2a2014ebd..6ae924d95cbc 100644 >>> --- a/drivers/usb/dwc3/gadget.c >>> +++ b/drivers/usb/dwc3/gadget.c >>> @@ -2751,6 +2751,8 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc) >>> break; >>> } >>> >>> + 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. interesting... I have never seen such bug before. Got some tracepoints of the problem? Also, if it's a bug, why wasn't it sent as a separate patch with a Cc stable and a Fixes tag? -- balbi
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