UPSTREAM: usb: dwc3: gadget: split __dwc3_gadget_kick_transfer()

To aid code readability, we're gonna split
__dwc3_gadget_kick_transfer() into its constituent
parts: scatter gather and linear buffers.

That way, it's easier to follow the code and focus
debug effort when one or the other fails.

Change-Id: I5116b050ab757a177df9e4fe40996b215f6eb2e0
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Wu Liang feng <wulf@rock-chips.com>
(cherry picked from commit 5ee85d890f8de5c6f1ab22ba13734a63fdf3ff2d)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 5be65bd6667a68511ede6e8f81b08bf0fd1173cf..a7c40a7aa018d466a567d317433dc35067a2ed7f 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -903,6 +903,65 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
        return dep->trb_dequeue - dep->trb_enqueue;
 }
 
+static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
+               struct dwc3_request *req, unsigned int trbs_left)
+{
+       struct usb_request *request = &req->request;
+       struct scatterlist *sg = request->sg;
+       struct scatterlist *s;
+       unsigned int    last = false;
+       unsigned int    length;
+       dma_addr_t      dma;
+       int             i;
+
+       for_each_sg(sg, s, request->num_mapped_sgs, i) {
+               unsigned chain = true;
+
+               length = sg_dma_len(s);
+               dma = sg_dma_address(s);
+
+               if (sg_is_last(s)) {
+                       if (list_is_last(&req->list, &dep->pending_list))
+                               last = true;
+
+                       chain = false;
+               }
+
+               if (!trbs_left)
+                       last = true;
+
+               if (last)
+                       chain = false;
+
+               dwc3_prepare_one_trb(dep, req, dma, length,
+                               last, chain, i);
+
+               if (last)
+                       break;
+       }
+}
+
+static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
+               struct dwc3_request *req, unsigned int trbs_left)
+{
+       unsigned int    last = false;
+       unsigned int    length;
+       dma_addr_t      dma;
+
+       dma = req->request.dma;
+       length = req->request.length;
+
+       if (!trbs_left)
+               last = true;
+
+       /* Is this the last request? */
+       if (list_is_last(&req->list, &dep->pending_list))
+               last = true;
+
+       dwc3_prepare_one_trb(dep, req, dma, length,
+                       last, false, 0);
+}
+
 /*
  * dwc3_prepare_trbs - setup TRBs from requests
  * @dep: endpoint for which requests are being prepared
@@ -915,70 +974,19 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep)
 {
        struct dwc3_request     *req, *n;
        u32                     trbs_left;
-       unsigned int            last_one = 0;
 
        BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
 
        trbs_left = dwc3_calc_trbs_left(dep);
 
        list_for_each_entry_safe(req, n, &dep->pending_list, list) {
-               unsigned        length;
-               dma_addr_t      dma;
-               last_one = false;
-
-               if (req->request.num_mapped_sgs > 0) {
-                       struct usb_request *request = &req->request;
-                       struct scatterlist *sg = request->sg;
-                       struct scatterlist *s;
-                       int             i;
-
-                       for_each_sg(sg, s, request->num_mapped_sgs, i) {
-                               unsigned chain = true;
-
-                               length = sg_dma_len(s);
-                               dma = sg_dma_address(s);
-
-                               if (sg_is_last(s)) {
-                                       if (list_is_last(&req->list, &dep->pending_list))
-                                               last_one = true;
-
-                                       chain = false;
-                               }
-
-                               trbs_left--;
-                               if (!trbs_left)
-                                       last_one = true;
-
-                               if (last_one)
-                                       chain = false;
-
-                               dwc3_prepare_one_trb(dep, req, dma, length,
-                                               last_one, chain, i);
-
-                               if (last_one)
-                                       break;
-                       }
-
-                       if (last_one)
-                               break;
-               } else {
-                       dma = req->request.dma;
-                       length = req->request.length;
-                       trbs_left--;
-
-                       if (!trbs_left)
-                               last_one = true;
-
-                       /* Is this the last request? */
-                       if (list_is_last(&req->list, &dep->pending_list))
-                               last_one = true;
-
-                       dwc3_prepare_one_trb(dep, req, dma, length,
-                                       last_one, false, 0);
+               if (req->request.num_mapped_sgs > 0)
+                       dwc3_prepare_one_trb_sg(dep, req, trbs_left--);
+               else
+                       dwc3_prepare_one_trb_linear(dep, req, trbs_left--);
 
-                       if (last_one)
-                               break;
-               }
+               if (!trbs_left)
+                       return;
        }
 }