Hi,
Peter Chen <peter.chen@xxxxxxx> writes:
> Hi Balbi,
>
> When do configfs function add and remove stress test, I find dwc3
> gadget .pullup will timeout if there is a request on the way. Even I
what do you mean by "a request on the way"?
> enlarge the delay, there is still timeout for .pullup.
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index f13bef950951..e95955b6a225 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1827,6 +1827,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
> do {
> reg = dwc3_readl(dwc->regs, DWC3_DSTS);
> reg &= DWC3_DSTS_DEVCTRLHLT;
> + udelay(1);
> } while (--timeout && !(!is_on ^ !reg));
>
> if (!timeout)
> @@ -1861,6 +1862,8 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
> spin_lock_irqsave(&dwc->lock, flags);
> ret = dwc3_gadget_run_stop(dwc, is_on, false);
> spin_unlock_irqrestore(&dwc->lock, flags);
> + if (ret)
> + dev_err(dwc->dev, "%s:ret = %d\n", __func__, ret);
>
> return ret;
> }
>
> This timeout causes the NULL pointer issue for ethernet gadget, eg. NCM, the reason
> is ncm->notify_req is NULL, but the ncm_notify_complete is not called before .unbind is
> called. See below oops:
sounds like a bug in ncm. If we haven't connected to host side yet, we
can't really complete the request.
> It is very easy to reproduce it, just create ncm function,
> and sleep 1 second, then, remove it.
>
> I am not sure if it is the common issue for dwc3, there is no such
> requirement for chipidea and cadence3. Would you please have a check?
could you capture tracepoints of what's happening here?
--
balbi
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