diff options
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 3c3ced128c77..f15147f79d14 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1073,9 +1073,17 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) list_add_tail(&req->list, &dep->pending_list); - if (usb_endpoint_xfer_isoc(dep->endpoint.desc) && - dep->flags & DWC3_EP_PENDING_REQUEST) { - if (list_empty(&dep->started_list)) { + /* + * NOTICE: Isochronous endpoints should NEVER be prestarted. We must + * wait for a XferNotReady event so we will know what's the current + * (micro-)frame number. + * + * Without this trick, we are very, very likely gonna get Bus Expiry + * errors which will force us issue EndTransfer command. + */ + if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) { + if ((dep->flags & DWC3_EP_PENDING_REQUEST) && + list_empty(&dep->started_list)) { dwc3_stop_active_transfer(dwc, dep->number, true); dep->flags = DWC3_EP_ENABLED; } |