iwlwifi: on-screen event log dump

This feature enables the on-screen uCode event log dump. The original
method will append the event log to syslog; with this capability,
we also enable the user to write script to capture the
events which provide additional flexibility to help uCode debugging

Method
1) change to debugfs directory (sys/kernel/debug/phyX/iwlagn/data)
2) #cat log_event

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, 21 insertions, 3 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 822de46e4f34..ee5aed12a4b1 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -420,6 +420,23 @@ static ssize_t iwl_dbgfs_nvm_read(struct file *file,
         return ret;
 }
 
+static ssize_t iwl_dbgfs_log_event_read(struct file *file,
+                                         char __user *user_buf,
+                                         size_t count, loff_t *ppos)
+{
+        struct iwl_priv *priv = file->private_data;
+        char *buf;
+        int pos = 0;
+        ssize_t ret = -ENOMEM;
+
+        pos = priv->cfg->ops->lib->dump_nic_event_log(priv, true, &buf, true);
+        if (pos && buf) {
+                ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+                kfree(buf);
+        }
+        return ret;
+}
+
 static ssize_t iwl_dbgfs_log_event_write(struct file *file,
                                         const char __user *user_buf,
                                         size_t count, loff_t *ppos)
@@ -436,7 +453,8 @@ static ssize_t iwl_dbgfs_log_event_write(struct file *file,
         if (sscanf(buf, "%d", &event_log_flag) != 1)
                 return -EFAULT;
         if (event_log_flag == 1)
-                priv->cfg->ops->lib->dump_nic_event_log(priv, true);
+                priv->cfg->ops->lib->dump_nic_event_log(priv, true,
+                                                        NULL, false);
 
         return count;
 }
@@ -859,7 +877,7 @@ static ssize_t iwl_dbgfs_current_sleep_command_read(struct file *file,
 }
 
 DEBUGFS_READ_WRITE_FILE_OPS(sram);
-DEBUGFS_WRITE_FILE_OPS(log_event);
+DEBUGFS_READ_WRITE_FILE_OPS(log_event);
 DEBUGFS_READ_FILE_OPS(nvm);
 DEBUGFS_READ_FILE_OPS(stations);
 DEBUGFS_READ_FILE_OPS(channels);
@@ -1965,7 +1983,7 @@ int iwl_dbgfs_register(struct iwl_priv *priv, const char *name)
         DEBUGFS_ADD_DIR(debug, dbgfs->dir_drv);
         DEBUGFS_ADD_FILE(nvm, data, S_IRUSR);
         DEBUGFS_ADD_FILE(sram, data, S_IWUSR | S_IRUSR);
-        DEBUGFS_ADD_FILE(log_event, data, S_IWUSR);
+        DEBUGFS_ADD_FILE(log_event, data, S_IWUSR | S_IRUSR);
         DEBUGFS_ADD_FILE(stations, data, S_IRUSR);
         DEBUGFS_ADD_FILE(channels, data, S_IRUSR);
         DEBUGFS_ADD_FILE(status, data, S_IRUSR);