Commit 8dbbe48c authored by Thinh Nguyen's avatar Thinh Nguyen Committed by Felipe Balbi
Browse files

usb: dwc3: gadget: Revise setting IOC when no TRB left 



To keep the setting of interrupt-on-completion (IOC) when out of TRBs
consistent and easier to read, the caller of dwc3_prepare_one_trb()
will determine if the TRB must have IOC bit set. This also reduces the
number of times we need to call dwc3_calc_trbs_left(). Note that we only
care about setting IOC from insufficient number of TRBs for SG and not
linear requests (because we don't need to split linear requests).

Signed-off-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: default avatarFelipe Balbi <balbi@kernel.org>
parent f9cc581b

drivers/usb/dwc3/gadget.c

+9 −8
Original line number Diff line number Diff line
@@ -1034,8 +1034,7 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, 
			trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;

	}



	if ((!no_interrupt && !chain) || must_interrupt ||

			(dwc3_calc_trbs_left(dep) == 1))

	if ((!no_interrupt && !chain) || must_interrupt)

		trb->ctrl |= DWC3_TRB_CTRL_IOC;



	if (chain)
@@ -1169,6 +1168,7 @@ static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep, 
		length -= sg_dma_len(s);



	for_each_sg(sg, s, remaining, i) {

		unsigned int num_trbs_left = dwc3_calc_trbs_left(dep);

		unsigned int trb_length;

		bool must_interrupt = false;

		bool last_sg = false;
@@ -1187,7 +1187,7 @@ static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep, 
		if ((i == remaining - 1) || !length)

			last_sg = true;



		if (!dwc3_calc_trbs_left(dep))

		if (!num_trbs_left)

			break;



		if (last_sg) {
@@ -1196,12 +1196,13 @@ static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep, 
		} else {

			/*

			 * Look ahead to check if we have enough TRBs for the

			 * last SG entry. If not, set interrupt on this TRB to

			 * resume preparing the last SG entry when more TRBs are

			 * next SG entry. If not, set interrupt on this TRB to

			 * resume preparing the next SG entry when more TRBs are

			 * free.

			 */

			if (needs_extra_trb && dwc3_calc_trbs_left(dep) <= 2 &&

					sg_dma_len(sg_next(s)) >= length)

			if (num_trbs_left == 1 || (needs_extra_trb &&

					num_trbs_left <= 2 &&

					sg_dma_len(sg_next(s)) >= length))

				must_interrupt = true;



			dwc3_prepare_one_trb(dep, req, trb_length, 1, i, false,
@@ -1230,7 +1231,7 @@ static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep, 
			break;

		}



		if (!dwc3_calc_trbs_left(dep) || must_interrupt)

		if (must_interrupt)

			break;

	}

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