From a2841f41d07fc85cf47d13fda30e254c5413e514 Mon Sep 17 00:00:00 2001 From: Thinh Nguyen Date: Thu, 24 Sep 2020 01:21:36 -0700 Subject: [PATCH] usb: dwc3: gadget: Improve TRB ZLP setup For OUT requests that requires extra TRBs for ZLP. We don't need to prepare the 0-length TRB and simply prepare the MPS size TRB. This reduces 1 TRB needed to prepare for ZLP. Signed-off-by: Thinh Nguyen Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 50 ++++++++++++++------------------------- 1 file changed, 18 insertions(+), 32 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index e74d97aa8b53..97790f55be1a 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1132,11 +1132,12 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, chain = false; if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) { - req->needs_extra_trb = true; - /* prepare normal TRB */ - dwc3_prepare_one_trb(dep, req, trb_length, + if (req->request.length) { + req->needs_extra_trb = true; + dwc3_prepare_one_trb(dep, req, trb_length, true, i, false); + } /* Now prepare one extra TRB to align transfer size */ dwc3_prepare_one_trb(dep, req, maxp - rem, @@ -1151,13 +1152,9 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, true, i, false); /* Prepare one extra TRB to handle ZLP */ - dwc3_prepare_one_trb(dep, req, 0, - !req->direction, 1, true); - - /* Prepare one more TRB to handle MPS alignment */ - if (!req->direction) - dwc3_prepare_one_trb(dep, req, maxp, - false, 1, true); + dwc3_prepare_one_trb(dep, req, + req->direction ? 0 : maxp, + false, 1, true); } else { dwc3_prepare_one_trb(dep, req, trb_length, chain, i, false); @@ -1198,10 +1195,11 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, unsigned int rem = length % maxp; if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) { - req->needs_extra_trb = true; - /* prepare normal TRB */ - dwc3_prepare_one_trb(dep, req, length, true, 0, false); + if (req->request.length) { + req->needs_extra_trb = true; + dwc3_prepare_one_trb(dep, req, length, true, 0, false); + } /* Now prepare one extra TRB to align transfer size */ dwc3_prepare_one_trb(dep, req, maxp - rem, false, 1, true); @@ -1214,11 +1212,8 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, dwc3_prepare_one_trb(dep, req, length, true, 0, false); /* Prepare one extra TRB to handle ZLP */ - dwc3_prepare_one_trb(dep, req, 0, !req->direction, 1, true); - - /* Prepare one more TRB to handle MPS alignment for OUT */ - if (!req->direction) - dwc3_prepare_one_trb(dep, req, maxp, false, 1, true); + dwc3_prepare_one_trb(dep, req, req->direction ? 0 : maxp, + false, 1, true); } else { dwc3_prepare_one_trb(dep, req, length, false, 0, false); } @@ -2621,12 +2616,12 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep, } /* - * If we're dealing with unaligned size OUT transfer, we will be left - * with one TRB pending in the ring. We need to manually clear HWO bit - * from that TRB. + * We use bounce buffer for requests that needs extra TRB or OUT ZLP. If + * this TRB points to the bounce buffer address, it's a MPS alignment + * TRB. Don't add it to req->remaining calculation. */ - - if (req->needs_extra_trb && !(trb->ctrl & DWC3_TRB_CTRL_CHN)) { + if (trb->bpl == lower_32_bits(dep->dwc->bounce_addr) && + trb->bph == upper_32_bits(dep->dwc->bounce_addr)) { trb->ctrl &= ~DWC3_TRB_CTRL_HWO; return 1; } @@ -2707,17 +2702,8 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep, goto out; if (req->needs_extra_trb) { - unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc); - ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event, status); - - /* Reclaim MPS padding TRB for ZLP */ - if (!req->direction && req->request.zero && req->request.length && - !usb_endpoint_xfer_isoc(dep->endpoint.desc) && - (IS_ALIGNED(req->request.length, maxp))) - ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event, status); - req->needs_extra_trb = false; }