{
        struct iguanair *ir = dev->priv;
        uint8_t space, *payload;
-       unsigned i, size, rc;
+       unsigned i, size, rc, bytes;
        struct send_packet *packet;
 
        mutex_lock(&ir->lock);
        /* convert from us to carrier periods */
        for (i = size = 0; i < count; i++) {
                txbuf[i] = DIV_ROUND_CLOSEST(txbuf[i] * ir->carrier, 1000000);
-               size += (txbuf[i] + 126) / 127;
+               bytes = (txbuf[i] + 126) / 127;
+               if (size + bytes > ir->bufsize) {
+                       count = i;
+                       break;
+               }
+               size += bytes;
        }
 
-       packet = kmalloc(sizeof(*packet) + size, GFP_KERNEL);
-       if (!packet) {
-               rc = -ENOMEM;
+       if (count == 0) {
+               rc = -EINVAL;
                goto out;
        }
 
-       if (size > ir->bufsize) {
-               rc = -E2BIG;
+       packet = kmalloc(sizeof(*packet) + size, GFP_KERNEL);
+       if (!packet) {
+               rc = -ENOMEM;
                goto out;
        }
 
                rc = iguanair_receiver(ir, false);
                if (rc) {
                        dev_warn(ir->dev, "disable receiver before transmit failed\n");
-                       goto out;
+                       goto out_kfree;
                }
        }
 
                        dev_warn(ir->dev, "re-enable receiver after transmit failed\n");
        }
 
+out_kfree:
+       kfree(packet);
 out:
        mutex_unlock(&ir->lock);
-       kfree(packet);
 
-       return rc;
+       return rc ? rc : count;
 }
 
 static int iguanair_open(struct rc_dev *rdev)
        ir = kzalloc(sizeof(*ir), GFP_KERNEL);
        rc = rc_allocate_device();
        if (!ir || !rc) {
-               ret = ENOMEM;
+               ret = -ENOMEM;
                goto out;
        }
 
        ir->urb_in = usb_alloc_urb(0, GFP_KERNEL);
 
        if (!ir->buf_in || !ir->urb_in) {
-               ret = ENOMEM;
+               ret = -ENOMEM;
                goto out;
        }