wifi: iwlwifi: mvm: Don't allow EMLSR when the RSSI is low

If the RSSI of a link is low enough, don't use it for EMLSR.
If EMLSR is already active and the RSSI of one of the links gets low,
exit EMLSR by deactivating that link.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240416134215.73263c000263.Ieb2b18855a2719b5e18ad2fa8a3e855ca4e23938@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 72 insertions, 9 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/link.c b/drivers/net/wireless/intel/iwlwifi/mvm/link.c
index 1171fc831ca8..ae45aa56d01d 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/link.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/link.c
@@ -537,7 +537,8 @@ u8 iwl_mvm_set_link_selection_data(struct ieee80211_vif *vif,
 			continue;
 
 		data[n_data].link_id = link_id;
-		data[n_data].band = link_conf->chanreq.oper.chan->band;
+		data[n_data].chandef = &link_conf->chanreq.oper;
+		data[n_data].signal = link_conf->bss->signal / 100;
 		data[n_data].grade = iwl_mvm_get_link_grade(link_conf);
 
 		if (data[n_data].grade > max_grade) {
@@ -550,21 +551,83 @@ u8 iwl_mvm_set_link_selection_data(struct ieee80211_vif *vif,
 	return n_data;
 }
 
+struct iwl_mvm_bw_to_rssi_threshs {
+	s8 low;
+	s8 high;
+};
+
+#define BW_TO_RSSI_THRESHOLDS(_bw)				\
+	[IWL_PHY_CHANNEL_MODE ## _bw] = {			\
+		.low = IWL_MVM_LOW_RSSI_THRESH_##_bw##MHZ,	\
+		.high = IWL_MVM_HIGH_RSSI_THRESH_##_bw##MHZ	\
+	}
+
+s8 iwl_mvm_get_esr_rssi_thresh(struct iwl_mvm *mvm,
+			       const struct cfg80211_chan_def *chandef,
+			       bool low)
+{
+	const struct iwl_mvm_bw_to_rssi_threshs bw_to_rssi_threshs_map[] = {
+		BW_TO_RSSI_THRESHOLDS(20),
+		BW_TO_RSSI_THRESHOLDS(40),
+		BW_TO_RSSI_THRESHOLDS(80),
+		BW_TO_RSSI_THRESHOLDS(160)
+		/* 320 MHz has the same thresholds as 20 MHz */
+	};
+	const struct iwl_mvm_bw_to_rssi_threshs *threshs;
+	u8 chan_width = iwl_mvm_get_channel_width(chandef);
+
+	if (WARN_ON(chandef->chan->band != NL80211_BAND_2GHZ &&
+		    chandef->chan->band != NL80211_BAND_5GHZ &&
+		    chandef->chan->band != NL80211_BAND_6GHZ))
+		return S8_MAX;
+
+	/* 6 GHz will always use 20 MHz thresholds, regardless of the BW */
+	if (chan_width == IWL_PHY_CHANNEL_MODE320)
+		chan_width = IWL_PHY_CHANNEL_MODE20;
+
+	threshs = &bw_to_rssi_threshs_map[chan_width];
+
+	return low ? threshs->low : threshs->high;
+}
+
+static u32
+iwl_mvm_esr_disallowed_with_link(struct ieee80211_vif *vif,
+				 const struct iwl_mvm_link_sel_data *link)
+{
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	struct iwl_mvm *mvm = mvmvif->mvm;
+	enum iwl_mvm_esr_state ret = 0;
+	s8 thresh;
+
+	/* BT Coex effects eSR mode only if one of the links is on LB */
+	if (link->chandef->chan->band == NL80211_BAND_2GHZ &&
+	    mvmvif->esr_disable_reason & IWL_MVM_ESR_BLOCKED_COEX)
+		ret |= IWL_MVM_ESR_BLOCKED_COEX;
+	thresh = iwl_mvm_get_esr_rssi_thresh(mvm, link->chandef,
+					     false);
+
+	if (link->signal < thresh)
+		ret |= IWL_MVM_ESR_EXIT_LOW_RSSI;
+
+	if (ret)
+		IWL_DEBUG_INFO(mvm,
+			       "Link %d is not allowed for esr. Reason: 0x%x\n",
+			       link->link_id, ret);
+	return ret;
+}
+
 VISIBLE_IF_IWLWIFI_KUNIT
 bool iwl_mvm_mld_valid_link_pair(struct ieee80211_vif *vif,
 				 const struct iwl_mvm_link_sel_data *a,
 				 const struct iwl_mvm_link_sel_data *b)
 {
-	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
-
-	if (a->band == b->band)
+	/* Per-link considerations */
+	if (iwl_mvm_esr_disallowed_with_link(vif, a) ||
+	    iwl_mvm_esr_disallowed_with_link(vif, b))
 		return false;
 
-	/* BT Coex effects eSR mode only if one of the link is on LB */
-	if (a->band == NL80211_BAND_2GHZ || b->band == NL80211_BAND_2GHZ)
-		return !(mvmvif->esr_disable_reason & IWL_MVM_ESR_BLOCKED_COEX);
-
-	return true;
+	/* Per-combination considerations */
+	return a->chandef->chan->band != b->chandef->chan->band;
 }
 EXPORT_SYMBOL_IF_IWLWIFI_KUNIT(iwl_mvm_mld_valid_link_pair);