usb: dwc3: gadget: avoid while (1) loop on completion

We know that we have to iterate over the list of
started requests. Instead of looping forever, we can
rely on list_for_each_entry(). Likewise, instead of
a do {} while loop over all, maybe available,
scatterlist entries, we can detect if $this request
uses scatterlist and rely on for_each_sg().

This makes the code easier to follow while making
sure that we will *always* break out of the loop.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 3cf4c9016b753ba207a44d4b0f6e226c2b4fe848..c776fb7f524a41823b0dce0c45403e6789e2789d 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1926,31 +1926,37 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
 static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
                const struct dwc3_event_depevt *event, int status)
 {
-       struct dwc3_request     *req;
+       struct dwc3_request     *req, *n;
        struct dwc3_trb         *trb;
-       unsigned int            i;
        int                     count = 0;
        int                     ret;
 
-       do {
-               int chain;
+       list_for_each_entry_safe(req, n, &dep->started_list, list) {
 
-               req = next_request(&dep->started_list);
-               if (!req)
-                       return 1;
+               int chain;
 
                chain = req->request.num_mapped_sgs > 0;
-               i = 0;
-               do {
+               if (chain) {
+                       struct scatterlist *sg = req->request.sg;
+                       struct scatterlist *s;
+                       unsigned int i;
+
+                       for_each_sg(sg, s, req->request.num_mapped_sgs, i) {
+                               trb = &dep->trb_pool[dep->trb_dequeue];
+                               count += trb->size & DWC3_TRB_SIZE_MASK;
+                               dwc3_ep_inc_deq(dep);
+
+                               ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
+                                               event, status, chain);
+                       }
+               } else {
                        trb = &dep->trb_pool[dep->trb_dequeue];
                        count += trb->size & DWC3_TRB_SIZE_MASK;
                        dwc3_ep_inc_deq(dep);
 
                        ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
                                        event, status, chain);
-                       if (ret)
-                               break;
-               } while (++i < req->request.num_mapped_sgs);
+               }
 
                /*
                 * We assume here we will always receive the entire data block
@@ -1964,7 +1970,7 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
 
                if (ret)
                        break;
-       } while (1);
+       }
 
        /*
         * Our endpoint might get disabled by another thread during