2 files changed, 16 insertions, 1 deletions

diff --git a/drivers/net/wimax/i2400m/i2400m.h b/drivers/net/wimax/i2400m/i2400m.h
index b8c7dbfead49..1babc55b1312 100644
--- a/drivers/net/wimax/i2400m/i2400m.h
+++ b/drivers/net/wimax/i2400m/i2400m.h
@@ -242,6 +242,11 @@ struct i2400m_barker_db;
  *     so we have a tx_blk_size variable that the bus layer sets to
  *     tell the engine how much of that we need.
  *
+ * @bus_tx_room_min: [fill] Minimum room required while allocating
+ *     TX queue's buffer space for message header. SDIO requires
+ *     224 bytes and USB 16 bytes. Refer bus specific driver code
+ *     for details.
+ *
  * @bus_pl_size_max: [fill] Maximum payload size.
  *
  * @bus_setup: [optional fill] Function called by the bus-generic code
@@ -573,6 +578,7 @@ struct i2400m {
         wait_queue_head_t state_wq;     /* Woken up when on state updates */
 
         size_t bus_tx_block_size;
+        size_t bus_tx_room_min;
         size_t bus_pl_size_max;
         unsigned bus_bm_retries;
 
diff --git a/drivers/net/wimax/i2400m/tx.c b/drivers/net/wimax/i2400m/tx.c
index 609f1ca6e9fc..3f819efc06b5 100644
--- a/drivers/net/wimax/i2400m/tx.c
+++ b/drivers/net/wimax/i2400m/tx.c
@@ -563,8 +563,17 @@ void i2400m_tx_new(struct i2400m *i2400m)
         struct i2400m_msg_hdr *tx_msg;
         bool try_head = 0;
         BUG_ON(i2400m->tx_msg != NULL);
+        /*
+         * In certain situations, TX queue might have enough space to
+         * accommodate the new message header I2400M_TX_PLD_SIZE, but
+         * might not have enough space to accommodate the payloads.
+         * Adding bus_tx_room_min padding while allocating a new TX message
+         * increases the possibilities of including at least one payload of the
+         * size <= bus_tx_room_min.
+         */
 try_head:
-        tx_msg = i2400m_tx_fifo_push(i2400m, I2400M_TX_PLD_SIZE, 0, try_head);
+        tx_msg = i2400m_tx_fifo_push(i2400m, I2400M_TX_PLD_SIZE,
+                                     i2400m->bus_tx_room_min, try_head);
         if (tx_msg == NULL)
                 goto out;
         else if (tx_msg == TAIL_FULL) {