UPSTREAM: usb: dwc3: gadget: use allocated/queued reqs for LST bit

Let's only set LST bit when we run out of space in
our TRB ring. For all other cases, we keep LST bit
unset which will prevent constant allocation and
deallocation of endpoint transfer resources.

Change-Id: Ia846ea0e3540c151d04488f239eb0f847c85b1fd
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Wu Liang feng <wulf@rock-chips.com>
(cherry picked from commit 55a0237f8f47957163125e20ee9260538c5c341c)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 2d3a6c8c4e514c3e3259d3dd05b2e134b2954165..2d13adb7649fa204a92638033de433cbd8b045ca 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -897,7 +897,8 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
 }
 
 static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
-               struct dwc3_request *req, unsigned int trbs_left)
+               struct dwc3_request *req, unsigned int trbs_left,
+               unsigned int more_coming)
 {
        struct usb_request *request = &req->request;
        struct scatterlist *sg = request->sg;
@@ -914,7 +915,8 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                dma = sg_dma_address(s);
 
                if (sg_is_last(s)) {
-                       if (list_is_last(&req->list, &dep->pending_list))
+                       if (usb_endpoint_xfer_int(dep->endpoint.desc) ||
+                               !more_coming)
                                last = true;
 
                        chain = false;
@@ -935,7 +937,8 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
 }
 
 static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
-               struct dwc3_request *req, unsigned int trbs_left)
+               struct dwc3_request *req, unsigned int trbs_left,
+               unsigned int more_coming)
 {
        unsigned int    last = false;
        unsigned int    length;
@@ -948,7 +951,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
                last = true;
 
        /* Is this the last request? */
-       if (list_is_last(&req->list, &dep->pending_list))
+       if (usb_endpoint_xfer_int(dep->endpoint.desc) || !more_coming)
                last = true;
 
        dwc3_prepare_one_trb(dep, req, dma, length,
@@ -966,6 +969,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
 static void dwc3_prepare_trbs(struct dwc3_ep *dep)
 {
        struct dwc3_request     *req, *n;
+       unsigned int            more_coming;
        u32                     trbs_left;
 
        BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
@@ -974,11 +978,15 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep)
        if (!trbs_left)
                return;
 
+       more_coming = dep->allocated_requests - dep->queued_requests;
+
        list_for_each_entry_safe(req, n, &dep->pending_list, list) {
                if (req->request.num_mapped_sgs > 0)
-                       dwc3_prepare_one_trb_sg(dep, req, trbs_left--);
+                       dwc3_prepare_one_trb_sg(dep, req, trbs_left--,
+                                       more_coming);
                else
-                       dwc3_prepare_one_trb_linear(dep, req, trbs_left--);
+                       dwc3_prepare_one_trb_linear(dep, req, trbs_left--,
+                                       more_coming);
 
                if (!trbs_left)
                        return;