iwlwifi: new debugging feature for dumping data traffic

The traffic buffer will only beallocated and used if either bit 23
(IWL_DX_TX) or bit 24 (IWL_DL_RX) of "debug" is set;
example: "debug=0x800000" - log tx data traffic
         "debug=0x1000000" - log rx data traffic
         "debug=0x1800000" - log both tx and rx traffic

The traffic log will store the beginning portion (64 bytes)  of the
latest 256 of tx and rx packets in the round-robbin buffer for
debugging,
user can examine the log through debugfs file.

How to display the current logged tx/rx traffic and txfifo and rxfifo
read/write point:
"cat traffic_log" in /sys/kernel/debug/ieee80211/phy0/iwlagn/debug
directory

By echo "0" to traffic_log file will empty the traffic log buffer and
reset both tx and rx taffic log index to 0.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 24c1ae6b8162..c9a1aacb2437 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -2476,9 +2476,12 @@ static ssize_t store_debug_level(struct device *d,
         ret = strict_strtoul(buf, 0, &val);
         if (ret)
                 IWL_ERR(priv, "%s is not in hex or decimal form.\n", buf);
-        else
+        else {
                 priv->debug_level = val;
-
+                if (iwl_alloc_traffic_mem(priv))
+                        IWL_ERR(priv,
+                                "Not enough memory to generate traffic log\n");
+        }
         return strnlen(buf, count);
 }
 
@@ -2819,6 +2822,8 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 #ifdef CONFIG_IWLWIFI_DEBUG
         atomic_set(&priv->restrict_refcnt, 0);
 #endif
+        if (iwl_alloc_traffic_mem(priv))
+                IWL_ERR(priv, "Not enough memory to generate traffic log\n");
 
         /**************************
          * 2. Initializing PCI bus
@@ -3003,6 +3008,7 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         pci_disable_device(pdev);
  out_ieee80211_free_hw:
         ieee80211_free_hw(priv->hw);
+        iwl_free_traffic_mem(priv);
  out:
         return err;
 }
@@ -3061,6 +3067,7 @@ static void __devexit iwl_pci_remove(struct pci_dev *pdev)
          * until now... */
         destroy_workqueue(priv->workqueue);
         priv->workqueue = NULL;
+        iwl_free_traffic_mem(priv);
 
         free_irq(priv->pci_dev->irq, priv);
         pci_disable_msi(priv->pci_dev);