On Tue, Oct 03, 2017 at 06:41:54PM +0000, Thinh Nguyen wrote:
> Hi,
>
> On 9/11/2017 12:42 AM, Felipe Balbi wrote:
> >
> > Hi,
> >
> > Thinh Nguyen <thinh.ngu...@synopsys.com> writes:
> >>> Felipe Balbi <ba...@kernel.org> writes:
> >>>> Thinh Nguyen <thinh.ngu...@synopsys.com> writes:
> >>>>
> >>>>> Hi Felipe,
> >>>>>
> >>>>> On 9/7/2017 12:16 AM, Felipe Balbi wrote:
> >>>>>>>>> drivers/usb/dwc3/gadget.c | 8 +++++---
> >>>>>>>>> 1 file changed, 5 insertions(+), 3 deletions(-)
> >>>>>>>>>
> >>>>>>>>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> >>>>>>>>> index 9e41605a..6b299c7 100644
> >>>>>>>>> --- a/drivers/usb/dwc3/gadget.c
> >>>>>>>>> +++ b/drivers/usb/dwc3/gadget.c
> >>>>>>>>> @@ -191,14 +191,16 @@ void dwc3_gadget_giveback(struct dwc3_ep
> >>>>>>>>> *dep, struct dwc3_request *req,
> >>>>>>>>>
> >>>>>>>>> req->started = false;
> >>>>>>>>> list_del(&req->list);
> >>>>>>>>> - req->trb = NULL;
> >>>>>>>>> req->remaining = 0;
> >>>>>>>>>
> >>>>>>>>> if (req->request.status == -EINPROGRESS)
> >>>>>>>>> req->request.status = status;
> >>>>>>>>>
> >>>>>>>>> - usb_gadget_unmap_request_by_dev(dwc->sysdev,
> >>>>>>>>> - &req->request, req->direction);
> >>>>>>>>> + if (req->trb)
> >>>>>>>> This check does not account for control data transfer. TRBs for ep0
> >>>>>>>> are
> >>>>>>>> not set to its req->trb. ep0out request needs to be unmapped,
> >>>>>>>> otherwise
> >>>>>>>> device will receive bogus data.
> >>>>>>>>
> >>>>>>>> Our internal test showed that the device failed to interpret control
> >>>>>>>> data from host. I bisected to this patch.
> >>>>>>
> >>>>>> what was the testing? How can I reproduce it?
> >>>>>
> >>>>> This is a regression. The internal test found the issue when it does a
> >>>>> 3-stage Control Write Transfer. You can reproduce this issue with just 1
> >>>>> out data packet of size > 0. Read and check the data on control request
> >>>>> completion.
> >>>>
> >>>> okay, is this enough to fix the problem for you?
> >>>>
> >>>> modified drivers/usb/dwc3/ep0.c
> >>>> @@ -48,6 +48,9 @@ static void dwc3_ep0_prepare_one_trb(struct dwc3_ep
> >>>> *dep,
> >>>> dwc = dep->dwc;
> >>>> trb = &dwc->ep0_trb[dep->trb_enqueue];
> >>>>
> >>>> + if (!req->trb)
> >>>> + req->trb = trb;
> >>>> +
> >>>> if (chain)
> >>>> dep->trb_enqueue++;
> >>>
> >>> sorry, no. this is totally wrong :-) Here's a better version:
> >>>
> >>> modified drivers/usb/dwc3/ep0.c
> >>> @@ -990,6 +990,8 @@ static void __dwc3_ep0_do_control_data(struct dwc3
> >>> *dwc,
> >>> DWC3_TRBCTL_CONTROL_DATA,
> >>> true);
> >>>
> >>> + req->trb = &dwc->ep0_trb[dep->trb_enqueue - 1]; > +
> >>> /* Now prepare one extra TRB to align transfer size */
> >>> dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr,
> >>> maxpacket - rem,
> >>> @@ -1015,6 +1017,8 @@ static void __dwc3_ep0_do_control_data(struct dwc3
> >>> *dwc,
> >>> DWC3_TRBCTL_CONTROL_DATA,
> >>> true);
> >>>
> >>> + req->trb = &dwc->ep0_trb[dep->trb_enqueue - 1]; > +
> >>> /* Now prepare one extra TRB to align transfer size */
> >>> dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr,
> >>> 0, DWC3_TRBCTL_CONTROL_DATA,
> >>> @@ -1029,6 +1033,9 @@ static void __dwc3_ep0_do_control_data(struct dwc3
> >>> *dwc,
> >>> dwc3_ep0_prepare_one_trb(dep, req->request.dma,
> >>> req->request.length,
> >>> DWC3_TRBCTL_CONTROL_DATA,
> >>> false);
> >>> +
> >>> + req->trb = &dwc->ep0_trb[dep->trb_enqueue];
> >>> +
> >>> ret = dwc3_ep0_start_trans(dep);
> >>> }
> >>>
> >>> (didn't even compile test)
> >>>
> >>>
> >>
> >> Yes this works.
> >
> > Thank you, I'll send this as a formal patch after merge window closes.
> >
>
> The fix for this patch is now in mainline. Please also apply it to
> stable kernel 4.13.x. Otherwise this regression will remain for the
> kernel 4.13.x.
>
> Upstream:
> commit 551684708356 ("usb: dwc3: ep0: fix DMA starvation by assigning
> req->trb on ep0")
Now queued up, thanks.
greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
