iwlwifi: add disable_11ac module param

Add module parameter that disables VHT capabilities.
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-drv.c

@@ -1719,3 +1719,7 @@ MODULE_PARM_DESC(fw_monitor,
 module_param_named(d0i3_timeout, iwlwifi_mod_params.d0i3_entry_delay,
 		   uint, S_IRUGO);
 MODULE_PARM_DESC(d0i3_timeout, "Timeout to D0i3 entry when idle (ms)");
+
+module_param_named(disable_11ac, iwlwifi_mod_params.disable_11ac, bool,
+		   S_IRUGO);
+MODULE_PARM_DESC(disable_11ac, "Disable VHT capabilities");

drivers/net/wireless/intel/iwlwifi/iwl-modparams.h

@@ -115,6 +115,7 @@ enum iwl_amsdu_size {
  *	entering D0i3 (in msecs)
  * @lar_disable: disable LAR (regulatory), default = 0
  * @fw_monitor: allow to use firmware monitor
+ * @disable_11ac: disable VHT capabilities, default = false.
  */
 struct iwl_mod_params {
 	int sw_crypto;
@@ -135,6 +136,7 @@ struct iwl_mod_params {
 	unsigned int d0i3_entry_delay;
 	bool lar_disable;
 	bool fw_monitor;
+	bool disable_11ac;
 };
 
 #endif /* #__iwl_modparams_h__ */

drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c

@@ -452,7 +452,7 @@ static void iwl_init_sbands(struct device *dev, const struct iwl_cfg *cfg,
 					  IEEE80211_BAND_5GHZ);
 	iwl_init_ht_hw_capab(cfg, data, &sband->ht_cap, IEEE80211_BAND_5GHZ,
 			     tx_chains, rx_chains);
-	if (data->sku_cap_11ac_enable)
+	if (data->sku_cap_11ac_enable && !iwlwifi_mod_params.disable_11ac)
 		iwl_init_vht_hw_capab(cfg, data, &sband->vht_cap,
 				      tx_chains, rx_chains);