+/* Callers must hold xpad->odata_lock spinlock */
+static bool xpad_prepare_next_out_packet(struct usb_xpad *xpad)
+{
+ struct xpad_output_packet *pkt, *packet = NULL;
+ int i;
+
+ for (i = 0; i < XPAD_NUM_OUT_PACKETS; i++) {
+ if (++xpad->last_out_packet >= XPAD_NUM_OUT_PACKETS)
+ xpad->last_out_packet = 0;
+
+ pkt = &xpad->out_packets[xpad->last_out_packet];
+ if (pkt->pending) {
+ dev_dbg(&xpad->intf->dev,
+ "%s - found pending output packet %d\n",
+ __func__, xpad->last_out_packet);
+ packet = pkt;
+ break;
+ }
+ }
+
+ if (packet) {
+ memcpy(xpad->odata, packet->data, packet->len);
+ xpad->irq_out->transfer_buffer_length = packet->len;
+ packet->pending = false;
+ return true;
+ }
+
+ return false;
+}
+
+/* Callers must hold xpad->odata_lock spinlock */
+static int xpad_try_sending_next_out_packet(struct usb_xpad *xpad)
+{
+ int error;
+
+ if (!xpad->irq_out_active && xpad_prepare_next_out_packet(xpad)) {
+ error = usb_submit_urb(xpad->irq_out, GFP_ATOMIC);
+ if (error) {
+ dev_err(&xpad->intf->dev,
+ "%s - usb_submit_urb failed with result %d\n",
+ __func__, error);
+ return -EIO;
+ }
+
+ xpad->irq_out_active = true;
+ }
+
+ return 0;
+}
+