usb: dwc3: gadget: Refactor preparing extra TRB

When the driver prepares the extra TRB, it uses bounce buffer. If we
just add a new parameter to dwc3_prepare_one_trb() to indicate this,
then we can refactor and simplify the driver quite a bit.
dwc3_prepare_one_trb() also checks if a request had been moved to the
started list. This is a prerequisite to subsequence patches improving
the handling of extra 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 173421508635a17cdd2940a5b4282f51f3fa3db6..e74d97aa8b53ed7250ccb03aea54b65f966caf71 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1060,10 +1060,11 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
  * @trb_length: buffer size of the TRB
  * @chain: should this TRB be chained to the next?
  * @node: only for isochronous endpoints. First TRB needs different type.
+ * @use_bounce_buffer: set to use bounce buffer
  */
 static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
                struct dwc3_request *req, unsigned int trb_length,
-               unsigned int chain, unsigned int node)
+               unsigned int chain, unsigned int node, bool use_bounce_buffer)
 {
        struct dwc3_trb         *trb;
        dma_addr_t              dma;
@@ -1072,7 +1073,9 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
        unsigned int            no_interrupt = req->request.no_interrupt;
        unsigned int            is_last = req->request.is_last;
 
-       if (req->request.num_sgs > 0)
+       if (use_bounce_buffer)
+               dma = dep->dwc->bounce_addr;
+       else if (req->request.num_sgs > 0)
                dma = sg_dma_address(req->start_sg);
        else
                dma = req->request.dma;
@@ -1129,56 +1132,35 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                        chain = false;
 
                if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
-                       struct dwc3     *dwc = dep->dwc;
-                       struct dwc3_trb *trb;
-
                        req->needs_extra_trb = true;
 
                        /* prepare normal TRB */
-                       dwc3_prepare_one_trb(dep, req, trb_length, true, i);
+                       dwc3_prepare_one_trb(dep, req, trb_length,
+                                       true, i, false);
 
                        /* Now prepare one extra TRB to align transfer size */
-                       trb = &dep->trb_pool[dep->trb_enqueue];
-                       req->num_trbs++;
-                       __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,
-                                       maxp - rem, false, 1,
-                                       req->request.stream_id,
-                                       req->request.short_not_ok,
-                                       req->request.no_interrupt,
-                                       req->request.is_last);
+                       dwc3_prepare_one_trb(dep, req, maxp - rem,
+                                       false, 1, true);
                } else if (req->request.zero && req->request.length &&
                           !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
                           !rem && !chain) {
-                       struct dwc3     *dwc = dep->dwc;
-                       struct dwc3_trb *trb;
-
                        req->needs_extra_trb = true;
 
                        /* Prepare normal TRB */
-                       dwc3_prepare_one_trb(dep, req, trb_length, true, i);
+                       dwc3_prepare_one_trb(dep, req, trb_length,
+                                       true, i, false);
 
                        /* Prepare one extra TRB to handle ZLP */
-                       trb = &dep->trb_pool[dep->trb_enqueue];
-                       req->num_trbs++;
-                       __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
-                                              !req->direction, 1,
-                                              req->request.stream_id,
-                                              req->request.short_not_ok,
-                                              req->request.no_interrupt,
-                                              req->request.is_last);
+                       dwc3_prepare_one_trb(dep, req, 0,
+                                       !req->direction, 1, true);
 
                        /* Prepare one more TRB to handle MPS alignment */
-                       if (!req->direction) {
-                               trb = &dep->trb_pool[dep->trb_enqueue];
-                               req->num_trbs++;
-                               __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,
-                                                      false, 1, req->request.stream_id,
-                                                      req->request.short_not_ok,
-                                                      req->request.no_interrupt,
-                                                      req->request.is_last);
-                       }
+                       if (!req->direction)
+                               dwc3_prepare_one_trb(dep, req, maxp,
+                                               false, 1, true);
                } else {
-                       dwc3_prepare_one_trb(dep, req, trb_length, chain, i);
+                       dwc3_prepare_one_trb(dep, req, trb_length,
+                                       chain, i, false);
                }
 
                /*
@@ -1216,54 +1198,29 @@ 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)) {
-               struct dwc3     *dwc = dep->dwc;
-               struct dwc3_trb *trb;
-
                req->needs_extra_trb = true;
 
                /* prepare normal TRB */
-               dwc3_prepare_one_trb(dep, req, length, true, 0);
+               dwc3_prepare_one_trb(dep, req, length, true, 0, false);
 
                /* Now prepare one extra TRB to align transfer size */
-               trb = &dep->trb_pool[dep->trb_enqueue];
-               req->num_trbs++;
-               __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,
-                               false, 1, req->request.stream_id,
-                               req->request.short_not_ok,
-                               req->request.no_interrupt,
-                               req->request.is_last);
+               dwc3_prepare_one_trb(dep, req, maxp - rem, false, 1, true);
        } else if (req->request.zero && req->request.length &&
                   !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
                   (IS_ALIGNED(req->request.length, maxp))) {
-               struct dwc3     *dwc = dep->dwc;
-               struct dwc3_trb *trb;
-
                req->needs_extra_trb = true;
 
                /* prepare normal TRB */
-               dwc3_prepare_one_trb(dep, req, length, true, 0);
+               dwc3_prepare_one_trb(dep, req, length, true, 0, false);
 
                /* Prepare one extra TRB to handle ZLP */
-               trb = &dep->trb_pool[dep->trb_enqueue];
-               req->num_trbs++;
-               __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
-                               !req->direction, 1, req->request.stream_id,
-                               req->request.short_not_ok,
-                               req->request.no_interrupt,
-                               req->request.is_last);
+               dwc3_prepare_one_trb(dep, req, 0, !req->direction, 1, true);
 
                /* Prepare one more TRB to handle MPS alignment for OUT */
-               if (!req->direction) {
-                       trb = &dep->trb_pool[dep->trb_enqueue];
-                       req->num_trbs++;
-                       __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,
-                                              false, 1, req->request.stream_id,
-                                              req->request.short_not_ok,
-                                              req->request.no_interrupt,
-                                              req->request.is_last);
-               }
+               if (!req->direction)
+                       dwc3_prepare_one_trb(dep, req, maxp, false, 1, true);
        } else {
-               dwc3_prepare_one_trb(dep, req, length, false, 0);
+               dwc3_prepare_one_trb(dep, req, length, false, 0, false);
        }
 }