iwlwifi: configure missed beacon threshold

Add support to configure missed beacon threshold, by default, if receive
"missed beacon" notification from uCode and has more than 5 consecutive
beacon missed, then perform sensitivity calibration; with this change,
allow user to adjust the missed beacon threshold from debugfs in case
more sensitivity calibration required for better performance in noisy
environment

The default value (=5) should be good enough for the normal condition,
but for very noisy environment, more sensitivity calibration could help
improve the throughput, so by setting the missed beacon threshold to
lower number, user might experience better performance result.

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, 46 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index af00ad2afa1..02f80bc2130 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -2131,6 +2131,49 @@ static ssize_t iwl_dbgfs_fh_reg_read(struct file *file,
 	return ret;
 }
 
+static ssize_t iwl_dbgfs_missed_beacon_read(struct file *file,
+					char __user *user_buf,
+					size_t count, loff_t *ppos) {
+
+	struct iwl_priv *priv = file->private_data;
+	int pos = 0;
+	char buf[12];
+	const size_t bufsz = sizeof(buf);
+	ssize_t ret;
+
+	pos += scnprintf(buf + pos, bufsz - pos, "%d\n",
+			priv->missed_beacon_threshold);
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+	return ret;
+}
+
+static ssize_t iwl_dbgfs_missed_beacon_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;
+	int missed;
+
+	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, "%d", &missed) != 1)
+		return -EINVAL;
+
+	if (missed < IWL_MISSED_BEACON_THRESHOLD_MIN ||
+	    missed > IWL_MISSED_BEACON_THRESHOLD_MAX)
+		priv->missed_beacon_threshold =
+			IWL_MISSED_BEACON_THRESHOLD_DEF;
+	else
+		priv->missed_beacon_threshold = missed;
+
+	return count;
+}
+
 DEBUGFS_READ_FILE_OPS(rx_statistics);
 DEBUGFS_READ_FILE_OPS(tx_statistics);
 DEBUGFS_READ_WRITE_FILE_OPS(traffic_log);
@@ -2148,6 +2191,7 @@ DEBUGFS_WRITE_FILE_OPS(clear_traffic_statistics);
 DEBUGFS_WRITE_FILE_OPS(csr);
 DEBUGFS_READ_WRITE_FILE_OPS(ucode_tracing);
 DEBUGFS_READ_FILE_OPS(fh_reg);
+DEBUGFS_READ_WRITE_FILE_OPS(missed_beacon);
 
 /*
  * Create the debugfs files and directories
@@ -2200,6 +2244,7 @@ int iwl_dbgfs_register(struct iwl_priv *priv, const char *name)
 	DEBUGFS_ADD_FILE(clear_traffic_statistics, debug, S_IWUSR);
 	DEBUGFS_ADD_FILE(csr, debug, S_IWUSR);
 	DEBUGFS_ADD_FILE(fh_reg, debug, S_IRUSR);
+	DEBUGFS_ADD_FILE(missed_beacon, debug, S_IWUSR);
 	if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) != CSR_HW_REV_TYPE_3945) {
 		DEBUGFS_ADD_FILE(ucode_rx_stats, debug, S_IRUSR);
 		DEBUGFS_ADD_FILE(ucode_tx_stats, debug, S_IRUSR);
@@ -2260,6 +2305,7 @@ void iwl_dbgfs_unregister(struct iwl_priv *priv)
 			file_clear_traffic_statistics);
 	DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_csr);
 	DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_fh_reg);
+	DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_missed_beacon);
 	if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) != CSR_HW_REV_TYPE_3945) {
 		DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.
 			file_ucode_rx_stats);