usb: dwc3: gadget: Return the number of prepared TRBs

In preparation for fixing the check for number of remaining TRBs,
revise dwc3_prepare_one_trb_linear() and dwc3_prepare_one_trb_sg() to
return the number of prepared TRBs.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 97790f5..673a34b 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1094,7 +1094,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
                        stream_id, short_not_ok, no_interrupt, is_last);
 }
 
-static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
+static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                struct dwc3_request *req)
 {
        struct scatterlist *sg = req->start_sg;
@@ -1105,6 +1105,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
        unsigned int rem = length % maxp;
        unsigned int remaining = req->request.num_mapped_sgs
                - req->num_queued_sgs;
+       unsigned int num_trbs = req->num_trbs;
 
        /*
         * If we resume preparing the request, then get the remaining length of
@@ -1131,9 +1132,15 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                if ((i == remaining - 1) || !length)
                        chain = false;
 
+               if (!dwc3_calc_trbs_left(dep))
+                       break;
+
                if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
                        /* prepare normal TRB */
                        if (req->request.length) {
+                               if (dwc3_calc_trbs_left(dep) < 2)
+                                       goto out;
+
                                req->needs_extra_trb = true;
                                dwc3_prepare_one_trb(dep, req, trb_length,
                                        true, i, false);
@@ -1145,6 +1152,10 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                } else if (req->request.zero && req->request.length &&
                           !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
                           !rem && !chain) {
+
+                       if (dwc3_calc_trbs_left(dep) < 2)
+                               goto out;
+
                        req->needs_extra_trb = true;
 
                        /* Prepare normal TRB */
@@ -1185,18 +1196,28 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                if (!dwc3_calc_trbs_left(dep))
                        break;
        }
+
+out:
+       return req->num_trbs - num_trbs;
 }
 
-static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
+static int dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
                struct dwc3_request *req)
 {
        unsigned int length = req->request.length;
        unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
        unsigned int rem = length % maxp;
+       unsigned int num_trbs = req->num_trbs;
+
+       if (!dwc3_calc_trbs_left(dep))
+               goto out;
 
        if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {
                /* prepare normal TRB */
                if (req->request.length) {
+                       if (dwc3_calc_trbs_left(dep) < 2)
+                               goto out;
+
                        req->needs_extra_trb = true;
                        dwc3_prepare_one_trb(dep, req, length, true, 0, false);
                }
@@ -1206,6 +1227,10 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
        } else if (req->request.zero && req->request.length &&
                   !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
                   (IS_ALIGNED(req->request.length, maxp))) {
+
+               if (dwc3_calc_trbs_left(dep) < 2)
+                       goto out;
+
                req->needs_extra_trb = true;
 
                /* prepare normal TRB */
@@ -1215,8 +1240,14 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
                dwc3_prepare_one_trb(dep, req, req->direction ? 0 : maxp,
                                false, 1, true);
        } else {
+               if (!dwc3_calc_trbs_left(dep))
+                       goto out;
+
                dwc3_prepare_one_trb(dep, req, length, false, 0, false);
        }
+
+out:
+       return req->num_trbs - num_trbs;
 }
 
 /*