wifi: mac80211: allow disabling SMPS debugfs controls

There are cases in which we don't want the user to override the
smps mode, e.g. when SMPS should be disabled due to EMLSR. Add
a driver flag to disable SMPS overriding and don't override if
it is set.
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230608163202.ef129e80556c.I74a298fdc86b87074c95228d3916739de1400597@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1755,12 +1755,15 @@ struct ieee80211_channel_switch {
  * @IEEE80211_VIF_GET_NOA_UPDATE: request to handle NOA attributes
  *	and send P2P_PS notification to the driver if NOA changed, even
  *	this is not pure P2P vif.
+ * @IEEE80211_VIF_DISABLE_SMPS_OVERRIDE: disable user configuration of
+ *	SMPS mode via debugfs.
  */
 enum ieee80211_vif_flags {
 	IEEE80211_VIF_BEACON_FILTER		= BIT(0),
 	IEEE80211_VIF_SUPPORTS_CQM_RSSI		= BIT(1),
 	IEEE80211_VIF_SUPPORTS_UAPSD		= BIT(2),
 	IEEE80211_VIF_GET_NOA_UPDATE		= BIT(3),
+	IEEE80211_VIF_DISABLE_SMPS_OVERRIDE	= BIT(4),
 };
 
 

net/mac80211/debugfs_netdev.c

@@ -2,7 +2,7 @@
 /*
  * Copyright (c) 2006	Jiri Benc <jbenc@suse.cz>
  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
- * Copyright (C) 2020-2022 Intel Corporation
+ * Copyright (C) 2020-2023 Intel Corporation
  */
 
 #include <linux/kernel.h>
@@ -267,6 +267,9 @@ static int ieee80211_set_smps(struct ieee80211_link_data *link,
 	struct ieee80211_local *local = sdata->local;
 	int err;
 
+	if (sdata->vif.driver_flags & IEEE80211_VIF_DISABLE_SMPS_OVERRIDE)
+		return -EOPNOTSUPP;
+
 	if (!(local->hw.wiphy->features & NL80211_FEATURE_STATIC_SMPS) &&
 	    smps_mode == IEEE80211_SMPS_STATIC)
 		return -EINVAL;