[PATCH mt76-next 03/25] wifi: mt76: mt7996: only remove a BMC STA_REC that was added

[Felix Fietkau <nbd@nbd.name>]

mt7996_vif_link_add() defers the BMC STA_REC of a station interface to
BSS_CHANGED_BSSID or BSS_CHANGED_ASSOC. A link that
mt76_get_vif_phy_link() creates for a scan or ROC receives neither,
because it is not part of the vif links. mt7996_vif_link_destroy() still
sends a STA_REC removal for it at the end of each scan, and the firmware
rejects it:

  staRecFreeStaRec-1606 Err: u2ClientSupportCnt is already 0. (wcid 1087)
  staRecUniCmdUpdate, u2Tag 0x0 ret = 0xc0000001 not success

Record per link whether the firmware accepted its BMC STA_REC, and only
send the removal for such a link. This also covers a station link that
is torn down before its first BSSID or association update.

Fixes: 51b795d68cad ("wifi: mt76: connac: use peer address for station BMC entry")
Fixes: 69d54ce7491d ("wifi: mt76: mt7996: switch to single multi-radio wiphy")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 .../net/wireless/mediatek/mt76/mt7996/main.c   | 18 +++++++++++-------
 .../net/wireless/mediatek/mt76/mt7996/mt7996.h |  1 +
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index a2655784a13d..e8faa826e037 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -349,6 +349,7 @@ int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 		return -ENOSPC;
 
 	link->mld_idx = mld_idx;
+	link->bmc_sta_added = false;
 	link->csa_bcn_uploaded = false;
 	eth_zero_addr(link->bmc_bssid);
 	mlink->omac_idx = idx;
@@ -392,9 +393,10 @@ int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 	/* defer the first STA_REC of BMC entry to BSS_CHANGED_BSSID for STA
 	 * interface, since firmware only records BSSID when the entry is new
 	 */
-	if (vif->type != NL80211_IFTYPE_STATION)
-		mt7996_mcu_add_sta(dev, link_conf, NULL, link, NULL,
-				   CONN_STATE_PORT_SECURE, true);
+	if (vif->type != NL80211_IFTYPE_STATION &&
+	    !mt7996_mcu_add_sta(dev, link_conf, NULL, link, NULL,
+				CONN_STATE_PORT_SECURE, true))
+		link->bmc_sta_added = true;
 	rcu_assign_pointer(dev->mt76.wcid[idx], &msta_link->wcid);
 
 	if (!mlink->wcid->offchannel)
@@ -441,8 +443,9 @@ static void mt7996_vif_link_destroy(struct mt7996_phy *phy,
 	if (!link_conf)
 		link_conf = &vif->bss_conf;
 
-	mt7996_mcu_add_sta(dev, link_conf, NULL, link, NULL,
-			   CONN_STATE_DISCONNECT, false);
+	if (link->bmc_sta_added)
+		mt7996_mcu_add_sta(dev, link_conf, NULL, link, NULL,
+				   CONN_STATE_DISCONNECT, false);
 	mt7996_mcu_add_bss_info(phy, vif, link_conf, mlink, msta_link, false);
 	mt7996_mcu_add_dev_info(phy, vif, link_conf, mlink, false);
 
@@ -939,8 +942,9 @@ mt7996_vif_link_bss_add(struct mt7996_phy *phy, struct ieee80211_vif *vif,
 
 	mt7996_mcu_add_bss_info(phy, vif, link_conf, &link->mt76,
 				&link->msta_link, true);
-	mt7996_mcu_add_sta(phy->dev, link_conf, NULL, link, NULL,
-			   CONN_STATE_PORT_SECURE, newly);
+	if (!mt7996_mcu_add_sta(phy->dev, link_conf, NULL, link, NULL,
+				CONN_STATE_PORT_SECURE, newly))
+		link->bmc_sta_added = true;
 }
 
 static void
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
index 84edb905fe06..d30b4d689bac 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
@@ -295,6 +295,7 @@ struct mt7996_vif_link {
 
 	u8 mld_idx;
 	u8 bmc_bssid[ETH_ALEN];
+	bool bmc_sta_added;
 	bool csa_bcn_uploaded;
 };
 
-- 
2.47.3