From 30892cba55968fe244feac811cd00cc12b1a574b Mon Sep 17 00:00:00 2001 From: Thinh Nguyen Date: Thu, 24 Sep 2020 01:22:01 -0700 Subject: usb: dwc3: gadget: Set IOC if not enough for extra TRBs If we run out of TRBs because we need extra TRBs, make sure to set the IOC bit for the previously prepared TRB to get completion notification to free up TRBs to resume later. Signed-off-by: Thinh Nguyen Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers/usb/dwc3') diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index ec142724e85c..f091e107d9cb 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1197,7 +1197,27 @@ static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, break; } + return req->num_trbs - num_trbs; + out: + /* + * If we run out of TRBs for MPS alignment setup, then set IOC on the + * previous TRB to get notified for TRB completion to resume when more + * TRBs are available. + * + * Note: normally we shouldn't update the TRB after the HWO bit is set. + * However, the controller doesn't update its internal cache to handle + * the newly prepared TRBs until UPDATE_TRANSFER or START_TRANSFER + * command is executed. At this point, it doesn't happen yet, so we + * should be fine modifying it here. + */ + if (i) { + struct dwc3_trb *trb; + + trb = dwc3_ep_prev_trb(dep, dep->trb_enqueue); + trb->ctrl |= DWC3_TRB_CTRL_IOC; + } + return req->num_trbs - num_trbs; } -- cgit v1.2.3