Consider a scenario where cable disconnect happens when there is an active
usb reqest queued to the UDC. As part of the disconnect we would issue an
end transfer with no interrupt-on-completion before giving back this
request. Since we are giving back the request without skipping TRBs the
num_trbs field of dwc3_request still holds the stale value previously used.
Function drivers re-use same request for a given bind-unbind session and
hence their dwc3_request context gets preserved across cable
disconnect/connect. When such a request gets re-queued after cable connect,
we would increase the num_trbs field on top of the previous stale value
thus incorrectly representing the number of TRBs used. Fix this by
resetting num_trbs field before giving back the request.
Fixes: 09fe1f8d7e2f ("usb: dwc3: gadget: track number of TRBs per request")
Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
---
Changes in v2:
- Addressed Thinh's comment to reset num_trbs in dwc3_gadget_del_and_unmap_request
rather than calling skip_trbs.
- Modify the commit message to match the modification.
drivers/usb/dwc3/gadget.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 578804d..0ded919 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -198,6 +198,7 @@ static void dwc3_gadget_del_and_unmap_request(struct dwc3_ep *dep,
list_del(&req->list);
req->remaining = 0;
req->needs_extra_trb = false;
+ req->num_trbs = 0;
if (req->request.status == -EINPROGRESS)
req->request.status = status;
--
2.7.4
