wimax/i2400m: USB specific TX queue's minimum buffer room required fo…

…r new message

This patch specifies the TX queue's buffer room required by the
USB bus driver while allocating header space for a new message.
Please refer the documentation in the code.

Signed-off-by: Prasanna S. Panchamukhi <prasannax.s.panchamukhi@intel.com>

drivers/net/wimax/i2400m/usb.c

@@ -467,6 +467,13 @@ int i2400mu_probe(struct usb_interface *iface,
 	usb_set_intfdata(iface, i2400mu);
 
 	i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
+	/*
+	 * Room required in the Tx queue for USB message to accommodate
+	 * a smallest payload while allocating header space is 16 bytes.
+	 * Adding this room  for the new tx message increases the
+	 * possibilities of including any payload with size <= 16 bytes.
+	 */
+	i2400m->bus_tx_room_min = I2400MU_BLK_SIZE;
 	i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
 	i2400m->bus_setup = NULL;
 	i2400m->bus_dev_start = i2400mu_bus_dev_start;