iwlwifi: adding interrupt counter in debugfs for debugging

This patch adds interrupt statistics report to debugfs, this can help to
understand number of interrupts happened which including HW/SW error for
easier and better debugging.

in /sys/kernel/debug/ieee80211/phyN/iwlagn/data directory
use "cat interrupt" to view the current interrupt counter
use "echo 0 > interrupt" to clear interrupt counter

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>

6 files changed, 141 insertions, 3 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 9dda3d547d0..12de63e9c72 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -911,6 +911,7 @@ void iwl_rx_handle(struct iwl_priv *priv)
                         IWL_DEBUG_RX(priv, "r = %d, i = %d, %s, 0x%02x\n", r,
                                 i, get_cmd_string(pkt->hdr.cmd), pkt->hdr.cmd);
                         priv->rx_handlers[pkt->hdr.cmd] (priv, rxb);
+                        priv->isr_stats.rx_handlers[pkt->hdr.cmd]++;
                 } else {
                         /* No handling needed */
                         IWL_DEBUG_RX(priv,
@@ -1035,6 +1036,7 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
                 /* Tell the device to stop sending interrupts */
                 iwl_disable_interrupts(priv);
 
+                priv->isr_stats.hw++;
                 iwl_irq_handle_error(priv);
 
                 handled |= CSR_INT_BIT_HW_ERR;
@@ -1047,13 +1049,17 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
 #ifdef CONFIG_IWLWIFI_DEBUG
         if (priv->debug_level & (IWL_DL_ISR)) {
                 /* NIC fires this, but we don't use it, redundant with WAKEUP */
-                if (inta & CSR_INT_BIT_SCD)
+                if (inta & CSR_INT_BIT_SCD) {
                         IWL_DEBUG_ISR(priv, "Scheduler finished to transmit "
                                       "the frame/frames.\n");
+                        priv->isr_stats.sch++;
+                }
 
                 /* Alive notification via Rx interrupt will do the real work */
-                if (inta & CSR_INT_BIT_ALIVE)
+                if (inta & CSR_INT_BIT_ALIVE) {
                         IWL_DEBUG_ISR(priv, "Alive interrupt\n");
+                        priv->isr_stats.alive++;
+                }
         }
 #endif
         /* Safely ignore these bits for debug checks below */
@@ -1069,6 +1075,8 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
                 IWL_DEBUG_RF_KILL(priv, "RF_KILL bit toggled to %s.\n",
                                 hw_rf_kill ? "disable radio" : "enable radio");
 
+                priv->isr_stats.rfkill++;
+
                 /* driver only loads ucode once setting the interface up.
                  * the driver allows loading the ucode even if the radio
                  * is killed. Hence update the killswitch state here. The
@@ -1088,6 +1096,7 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
         /* Chip got too hot and stopped itself */
         if (inta & CSR_INT_BIT_CT_KILL) {
                 IWL_ERR(priv, "Microcode CT kill error detected.\n");
+                priv->isr_stats.ctkill++;
                 handled |= CSR_INT_BIT_CT_KILL;
         }
 
@@ -1095,6 +1104,8 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
         if (inta & CSR_INT_BIT_SW_ERR) {
                 IWL_ERR(priv, "Microcode SW error detected. "
                         " Restarting 0x%X.\n", inta);
+                priv->isr_stats.sw++;
+                priv->isr_stats.sw_err = inta;
                 iwl_irq_handle_error(priv);
                 handled |= CSR_INT_BIT_SW_ERR;
         }
@@ -1110,6 +1121,8 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
                 iwl_txq_update_write_ptr(priv, &priv->txq[4]);
                 iwl_txq_update_write_ptr(priv, &priv->txq[5]);
 
+                priv->isr_stats.wakeup++;
+
                 handled |= CSR_INT_BIT_WAKEUP;
         }
 
@@ -1118,19 +1131,23 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
          * notifications from uCode come through here*/
         if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX)) {
                 iwl_rx_handle(priv);
+                priv->isr_stats.rx++;
                 handled |= (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX);
         }
 
         if (inta & CSR_INT_BIT_FH_TX) {
                 IWL_DEBUG_ISR(priv, "Tx interrupt\n");
+                priv->isr_stats.tx++;
                 handled |= CSR_INT_BIT_FH_TX;
                 /* FH finished to write, send event */
                 priv->ucode_write_complete = 1;
                 wake_up_interruptible(&priv->wait_command_queue);
         }
 
-        if (inta & ~handled)
+        if (inta & ~handled) {
                 IWL_ERR(priv, "Unhandled INTA bits 0x%08x\n", inta & ~handled);
+                priv->isr_stats.unhandled++;
+        }
 
         if (inta & ~CSR_INI_SET_MASK) {
                 IWL_WARN(priv, "Disabled INTA bits 0x%08x were pending\n",
@@ -1155,6 +1172,7 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
         spin_unlock_irqrestore(&priv->lock, flags);
 }
 
+
 /******************************************************************************
  *
  * uCode download functions
@@ -1983,6 +2001,8 @@ static int iwl_mac_start(struct ieee80211_hw *hw)
 
 out:
         priv->is_open = 1;
+        /* default to MONITOR mode */
+        priv->iw_mode = NL80211_IFTYPE_MONITOR;
         IWL_DEBUG_MAC80211(priv, "leave\n");
         return 0;
 }
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index 5877293bd21..f2317524028 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -2119,6 +2119,12 @@ void iwl_rx_reply_error(struct iwl_priv *priv,
 }
 EXPORT_SYMBOL(iwl_rx_reply_error);
 
+void iwl_clear_isr_stats(struct iwl_priv *priv)
+{
+        memset(&priv->isr_stats, 0, sizeof(priv->isr_stats));
+}
+EXPORT_SYMBOL(iwl_clear_isr_stats);
+
 int iwl_mac_conf_tx(struct ieee80211_hw *hw, u16 queue,
                            const struct ieee80211_tx_queue_params *params)
 {
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index df90c261b6b..8773d733a54 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -480,6 +480,7 @@ int iwl_pci_resume(struct pci_dev *pdev);
 ******************************************************/
 void iwl_dump_nic_error_log(struct iwl_priv *priv);
 void iwl_dump_nic_event_log(struct iwl_priv *priv);
+void iwl_clear_isr_stats(struct iwl_priv *priv);
 
 /*****************************************************
 *  GEOS
diff --git a/drivers/net/wireless/iwlwifi/iwl-debug.h b/drivers/net/wireless/iwlwifi/iwl-debug.h
index 65d1a7f2db9..db069801bc4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debug.h
+++ b/drivers/net/wireless/iwlwifi/iwl-debug.h
@@ -75,6 +75,7 @@ struct iwl_debugfs {
                 struct dentry *file_log_event;
                 struct dentry *file_channels;
                 struct dentry *file_status;
+                struct dentry *file_interrupt;
         } dbgfs_data_files;
         struct dir_rf_files {
                 struct dentry *file_disable_sensitivity;
diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 5b8c83939bf..ffc4be3842b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -473,6 +473,95 @@ static ssize_t iwl_dbgfs_status_read(struct file *file,
         return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
 }
 
+static ssize_t iwl_dbgfs_interrupt_read(struct file *file,
+                                        char __user *user_buf,
+                                        size_t count, loff_t *ppos) {
+
+        struct iwl_priv *priv = (struct iwl_priv *)file->private_data;
+        int pos = 0;
+        int cnt = 0;
+        char *buf;
+        int bufsz = 24 * 64; /* 24 items * 64 char per item */
+        ssize_t ret;
+
+        buf = kzalloc(bufsz, GFP_KERNEL);
+        if (!buf) {
+                IWL_ERR(priv, "Can not allocate Buffer\n");
+                return -ENOMEM;
+        }
+
+        pos += scnprintf(buf + pos, bufsz - pos,
+                        "Interrupt Statistics Report:\n");
+
+        pos += scnprintf(buf + pos, bufsz - pos, "HW Error:\t\t\t %u\n",
+                priv->isr_stats.hw);
+        pos += scnprintf(buf + pos, bufsz - pos, "SW Error:\t\t\t %u\n",
+                priv->isr_stats.sw);
+        if (priv->isr_stats.sw > 0) {
+                pos += scnprintf(buf + pos, bufsz - pos,
+                        "\tLast Restarting Code:  0x%X\n",
+                        priv->isr_stats.sw_err);
+        }
+#ifdef CONFIG_IWLWIFI_DEBUG
+        pos += scnprintf(buf + pos, bufsz - pos, "Frame transmitted:\t\t %u\n",
+                priv->isr_stats.sch);
+        pos += scnprintf(buf + pos, bufsz - pos, "Alive interrupt:\t\t %u\n",
+                priv->isr_stats.alive);
+#endif
+        pos += scnprintf(buf + pos, bufsz - pos,
+                "HW RF KILL switch toggled:\t %u\n",
+                priv->isr_stats.rfkill);
+
+        pos += scnprintf(buf + pos, bufsz - pos, "CT KILL:\t\t\t %u\n",
+                priv->isr_stats.ctkill);
+
+        pos += scnprintf(buf + pos, bufsz - pos, "Wakeup Interrupt:\t\t %u\n",
+                priv->isr_stats.wakeup);
+
+        pos += scnprintf(buf + pos, bufsz - pos,
+                "Rx command responses:\t\t %u\n",
+                priv->isr_stats.rx);
+        for (cnt = 0; cnt < REPLY_MAX; cnt++) {
+                if (priv->isr_stats.rx_handlers[cnt] > 0)
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                "\tRx handler[%36s]:\t\t %u\n",
+                                get_cmd_string(cnt),
+                                priv->isr_stats.rx_handlers[cnt]);
+        }
+
+        pos += scnprintf(buf + pos, bufsz - pos, "Tx/FH interrupt:\t\t %u\n",
+                priv->isr_stats.tx);
+
+        pos += scnprintf(buf + pos, bufsz - pos, "Unexpected INTA:\t\t %u\n",
+                priv->isr_stats.unhandled);
+
+        ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+        kfree(buf);
+        return ret;
+}
+
+static ssize_t iwl_dbgfs_interrupt_write(struct file *file,
+                                         const char __user *user_buf,
+                                         size_t count, loff_t *ppos)
+{
+        struct iwl_priv *priv = file->private_data;
+        char buf[8];
+        int buf_size;
+        u32 reset_flag;
+
+        memset(buf, 0, sizeof(buf));
+        buf_size = min(count, sizeof(buf) -  1);
+        if (copy_from_user(buf, user_buf, buf_size))
+                return -EFAULT;
+        if (sscanf(buf, "%x", &reset_flag) != 1)
+                return -EFAULT;
+        if (reset_flag == 0)
+                iwl_clear_isr_stats(priv);
+
+        return count;
+}
+
+
 DEBUGFS_READ_WRITE_FILE_OPS(sram);
 DEBUGFS_WRITE_FILE_OPS(log_event);
 DEBUGFS_READ_FILE_OPS(eeprom);
@@ -481,6 +570,7 @@ DEBUGFS_READ_FILE_OPS(rx_statistics);
 DEBUGFS_READ_FILE_OPS(tx_statistics);
 DEBUGFS_READ_FILE_OPS(channels);
 DEBUGFS_READ_FILE_OPS(status);
+DEBUGFS_READ_WRITE_FILE_OPS(interrupt);
 
 /*
  * Create the debugfs files and directories
@@ -516,6 +606,7 @@ int iwl_dbgfs_register(struct iwl_priv *priv, const char *name)
         DEBUGFS_ADD_FILE(tx_statistics, data);
         DEBUGFS_ADD_FILE(channels, data);
         DEBUGFS_ADD_FILE(status, data);
+        DEBUGFS_ADD_FILE(interrupt, data);
         DEBUGFS_ADD_BOOL(disable_sensitivity, rf, &priv->disable_sens_cal);
         DEBUGFS_ADD_BOOL(disable_chain_noise, rf,
                          &priv->disable_chain_noise_cal);
@@ -546,6 +637,7 @@ void iwl_dbgfs_unregister(struct iwl_priv *priv)
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_data_files.file_stations);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_data_files.file_channels);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_data_files.file_status);
+        DEBUGFS_REMOVE(priv->dbgfs->dbgfs_data_files.file_interrupt);
         DEBUGFS_REMOVE(priv->dbgfs->dir_data);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_rf_files.file_disable_sensitivity);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_rf_files.file_disable_chain_noise);
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 59930f398f3..0922e33a7d4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -819,6 +819,21 @@ enum {
         MEASUREMENT_ACTIVE = (1 << 1),
 };
 
+/* interrupt statistics */
+struct isr_statistics {
+        u32 hw;
+        u32 sw;
+        u32 sw_err;
+        u32 sch;
+        u32 alive;
+        u32 rfkill;
+        u32 ctkill;
+        u32 wakeup;
+        u32 rx;
+        u32 rx_handlers[REPLY_MAX];
+        u32 tx;
+        u32 unhandled;
+};
 
 #define IWL_MAX_NUM_QUEUES      20 /* FIXME: do dynamic allocation */
 
@@ -975,6 +990,9 @@ struct iwl_priv {
                 u64 bytes;
         } tx_stats[3], rx_stats[3];
 
+        /* counts interrupts */
+        struct isr_statistics isr_stats;
+
         struct iwl_power_mgr power_data;
 
         struct iwl_notif_statistics statistics;