usb: dwc3: gadget: start requests as soon as they come
In an attempt to make dwc3 slightly faster, let's
start usb_requests as soon as they come as that will
let us avoid a XFER_NOT_READY event and save a little
bit of time.
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0429820..2d0dc2d 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1072,6 +1072,22 @@
list_add_tail(&req->list, &dep->request_list);
/*
+ * If there are no pending requests and the endpoint isn't already
+ * busy, we will just start the request straight away.
+ *
+ * This will save one IRQ (XFER_NOT_READY) and possibly make it a
+ * little bit faster.
+ */
+ if (!usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
+ !(dep->flags & DWC3_EP_BUSY)) {
+ ret = __dwc3_gadget_kick_transfer(dep, 0, true);
+ if (ret && ret != -EBUSY)
+ dev_dbg(dwc->dev, "%s: failed to kick transfers\n",
+ dep->name);
+ return ret;
+ }
+
+ /*
* There are a few special cases:
*
* 1. XferNotReady with empty list of requests. We need to kick the