iwlcore: Allow skb allocation from tasklet.

If RX queue becomes empty then we need to restock the queue from tasklet to prevent
ucode from starving. A caller to iwl_rx_allocate will decide if allocated buffer should
come from GFP_ATOMIC or GFP_KERNEL.

Signed-off-by: Mohamed Abbas <mohamed.abbas@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index fa24b019c62c..be1058bdc4c5 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -831,6 +831,7 @@ void iwl_rx_handle(struct iwl_priv *priv)
         unsigned long flags;
         u8 fill_rx = 0;
         u32 count = 8;
+        int total_empty;
 
         /* uCode's read index (stored in shared DRAM) indicates the last Rx
          * buffer that the driver may process (last buffer filled by ucode). */
@@ -841,7 +842,12 @@ void iwl_rx_handle(struct iwl_priv *priv)
         if (i == r)
                 IWL_DEBUG_RX(priv, "r = %d, i = %d\n", r, i);
 
-        if (iwl_rx_queue_space(rxq) > (RX_QUEUE_SIZE / 2))
+        /* calculate total frames need to be restock after handling RX */
+        total_empty = r - priv->rxq.write_actual;
+        if (total_empty < 0)
+                total_empty += RX_QUEUE_SIZE;
+
+        if (total_empty > (RX_QUEUE_SIZE / 2))
                 fill_rx = 1;
 
         while (i != r) {
@@ -918,7 +924,7 @@ void iwl_rx_handle(struct iwl_priv *priv)
                         count++;
                         if (count >= 8) {
                                 priv->rxq.read = i;
-                                iwl_rx_queue_restock(priv);
+                                iwl_rx_replenish_now(priv);
                                 count = 0;
                         }
                 }
@@ -926,7 +932,10 @@ void iwl_rx_handle(struct iwl_priv *priv)
 
         /* Backtrack one entry */
         priv->rxq.read = i;
-        iwl_rx_queue_restock(priv);
+        if (fill_rx)
+                iwl_rx_replenish_now(priv);
+        else
+                iwl_rx_queue_restock(priv);
 }
 
 /* call this function to flush any scheduled tasklet */