Hi,
Roger Quadros <rogerq@xxxxxx> writes:
>>>> irq/170-dwc3-1240 [000] d... 85.450564: dwc3_gadget_giveback: ep1out: req ee75d6ac length 0/256 zsI ==> -108
>>>> irq/170-dwc3-1240 [000] d... 85.450566: dwc3_gadget_giveback: ep1out: req c26c10a3 length 0/256 zsI ==> -108
>>>> irq/170-dwc3-1240 [000] d... 85.450567: dwc3_gadget_giveback: : req d4301893 length 0/0 zsI ==> 0
>>>
>>> Giveback happens on above two reqs after they are already freed. Could
>>> it be due to f_uac2 / u_audio.c performing usb_ep_free_request()
>>> immediately after usb_ep_dequeue() without waiting for completion?
>>
>> this could be a race condition. Add a trace_printk() at the cancelation,
>> see if the request is moved to cancelled list.
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 86dc1db788a9..affc2f7a929d 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -1513,6 +1513,7 @@ static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep)
>> struct dwc3_request *tmp;
>>
>> list_for_each_entry_safe(req, tmp, &dep->cancelled_list, list) {
>> + trace_printk("---> completing cancellation of req %p\n", req);
>> dwc3_gadget_ep_skip_trbs(dep, req);
>> dwc3_gadget_giveback(dep, req, -ECONNRESET);
>> }
>> @@ -1551,6 +1552,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
>> if (!r->trb)
>> goto out0;
>>
>> + trace_printk("---> req %p moved to cancelled\n", req);
>> dwc3_gadget_move_cancelled_request(req);
>> if (dep->flags & DWC3_EP_TRANSFER_STARTED)
>> goto out0;
>>
>>
>
> Below is trace with above debug patch applied.
Did it fail the same way? It doesn't look like in the trace.
Does this help?
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 86dc1db788a9..a9aba716bf80 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -707,6 +707,12 @@ static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep)
dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
}
+
+ while (!list_empty(&dep->cancelled_list)) {
+ req = next_request(&dep->cancelled_list);
+
+ dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
+ }
}
/**
--
balbi
