usb: dwc3: ep0: use immediate SETUP on TRB

If we pass TRB's own address on bpl/bph fields, we can get our SETUP
packet as immediate data on the TRB itself, without having to allocate
extra memory for it.

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 640e4aa..4787d6f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3144,27 +3144,19 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 
 	dwc->irq_gadget = irq;
 
-	dwc->ctrl_req = dma_alloc_coherent(dwc->sysdev, sizeof(*dwc->ctrl_req),
-			&dwc->ctrl_req_addr, GFP_KERNEL);
-	if (!dwc->ctrl_req) {
-		dev_err(dwc->dev, "failed to allocate ctrl request\n");
-		ret = -ENOMEM;
-		goto err0;
-	}
-
 	dwc->ep0_trb = dma_alloc_coherent(dwc->sysdev,
 					  sizeof(*dwc->ep0_trb) * 2,
 					  &dwc->ep0_trb_addr, GFP_KERNEL);
 	if (!dwc->ep0_trb) {
 		dev_err(dwc->dev, "failed to allocate ep0 trb\n");
 		ret = -ENOMEM;
-		goto err1;
+		goto err0;
 	}
 
 	dwc->setup_buf = kzalloc(DWC3_EP0_BOUNCE_SIZE, GFP_KERNEL);
 	if (!dwc->setup_buf) {
 		ret = -ENOMEM;
-		goto err2;
+		goto err1;
 	}
 
 	dwc->ep0_bounce = dma_alloc_coherent(dwc->sysdev,
@@ -3173,20 +3165,20 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 	if (!dwc->ep0_bounce) {
 		dev_err(dwc->dev, "failed to allocate ep0 bounce buffer\n");
 		ret = -ENOMEM;
-		goto err3;
+		goto err2;
 	}
 
 	dwc->zlp_buf = kzalloc(DWC3_ZLP_BUF_SIZE, GFP_KERNEL);
 	if (!dwc->zlp_buf) {
 		ret = -ENOMEM;
-		goto err4;
+		goto err3;
 	}
 
 	dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,
 			&dwc->bounce_addr, GFP_KERNEL);
 	if (!dwc->bounce) {
 		ret = -ENOMEM;
-		goto err5;
+		goto err4;
 	}
 
 	init_completion(&dwc->ep0_in_setup);
@@ -3226,38 +3218,34 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 
 	ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);
 	if (ret)
-		goto err6;
+		goto err5;
 
 	ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
 	if (ret) {
 		dev_err(dwc->dev, "failed to register udc\n");
-		goto err6;
+		goto err5;
 	}
 
 	return 0;
-err6:
+err5:
 	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
 			dwc->bounce_addr);
 
-err5:
+err4:
 	kfree(dwc->zlp_buf);
 
-err4:
+err3:
 	dwc3_gadget_free_endpoints(dwc);
 	dma_free_coherent(dwc->sysdev, DWC3_EP0_BOUNCE_SIZE,
 			dwc->ep0_bounce, dwc->ep0_bounce_addr);
 
-err3:
+err2:
 	kfree(dwc->setup_buf);
 
-err2:
+err1:
 	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
 			dwc->ep0_trb, dwc->ep0_trb_addr);
 
-err1:
-	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ctrl_req),
-			dwc->ctrl_req, dwc->ctrl_req_addr);
-
 err0:
 	return ret;
 }
@@ -3280,9 +3268,6 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 
 	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
 			dwc->ep0_trb, dwc->ep0_trb_addr);
-
-	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ctrl_req),
-			dwc->ctrl_req, dwc->ctrl_req_addr);
 }
 
 int dwc3_gadget_suspend(struct dwc3 *dwc)