diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 8e3e0c30f420e..1a1c9c80ee7ce 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -940,19 +940,19 @@ static struct dwc3_trb *dwc3_ep_prev_trb(struct dwc3_ep *dep, u8 index) static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep) { - struct dwc3_trb *tmp; u8 trbs_left; /* - * If enqueue & dequeue are equal than it is either full or empty. - * - * One way to know for sure is if the TRB right before us has HWO bit - * set or not. If it has, then we're definitely full and can't fit any - * more transfers in our ring. + * If the enqueue & dequeue are equal then the TRB ring is either full + * or empty. It's considered full when there are DWC3_TRB_NUM-1 of TRBs + * pending to be processed by the driver. */ if (dep->trb_enqueue == dep->trb_dequeue) { - tmp = dwc3_ep_prev_trb(dep, dep->trb_enqueue); - if (tmp->ctrl & DWC3_TRB_CTRL_HWO) + /* + * If there is any request remained in the started_list at + * this point, that means there is no TRB available. + */ + if (!list_empty(&dep->started_list)) return 0; return DWC3_TRB_NUM - 1;