wifi: mt76: add multi-radio support to scanning code

When scanning on a phy/vif combination that does not have an active link,
create a temporary link in order to ensure that we have a valid wcid.

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>

Author: nbd168

drivers/net/wireless/mediatek/mt76/channel.c

@@ -4,6 +4,20 @@
  */
 #include "mt76.h"
 
+static struct mt76_vif_link *
+mt76_alloc_mlink(struct mt76_dev *dev, struct mt76_vif_data *mvif)
+{
+	struct mt76_vif_link *mlink;
+
+	mlink = kzalloc(dev->drv->link_data_size, GFP_KERNEL);
+	if (!mlink)
+		return NULL;
+
+	mlink->mvif = mvif;
+
+	return mlink;
+}
+
 static int
 mt76_phy_update_channel(struct mt76_phy *phy,
 			struct ieee80211_chanctx_conf *conf)
@@ -108,7 +122,7 @@ int mt76_assign_vif_chanctx(struct ieee80211_hw *hw,
 
 	mlink = mt76_vif_conf_link(dev, vif, link_conf);
 	if (!mlink) {
-		mlink = kzalloc(dev->drv->link_data_size, GFP_KERNEL);
+		mlink = mt76_alloc_mlink(dev, mvif);
 		if (!mlink) {
 			ret = -ENOMEM;
 			goto out;
@@ -248,3 +262,49 @@ int mt76_switch_vif_chanctx(struct ieee80211_hw *hw,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(mt76_switch_vif_chanctx);
+
+struct mt76_vif_link *mt76_get_vif_phy_link(struct mt76_phy *phy,
+					    struct ieee80211_vif *vif)
+{
+	struct mt76_vif_link *mlink = (struct mt76_vif_link *)vif->drv_priv;
+	struct mt76_vif_data *mvif = mlink->mvif;
+	struct mt76_dev *dev = phy->dev;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(mvif->link); i++) {
+		mlink = mt76_dereference(mvif->link[i], dev);
+		if (!mlink)
+			continue;
+
+		if (mt76_vif_link_phy(mlink) == phy)
+			return mlink;
+	}
+
+	if (!dev->drv->vif_link_add)
+		return ERR_PTR(-EINVAL);
+
+	mlink = mt76_alloc_mlink(dev, mvif);
+	if (!mlink)
+		return ERR_PTR(-ENOMEM);
+
+	mlink->offchannel = true;
+	ret = dev->drv->vif_link_add(phy, vif, &vif->bss_conf, mlink);
+	if (ret) {
+		kfree(mlink);
+		return ERR_PTR(ret);
+	}
+
+	return mlink;
+}
+
+void mt76_put_vif_phy_link(struct mt76_phy *phy, struct ieee80211_vif *vif,
+			   struct mt76_vif_link *mlink)
+{
+	struct mt76_dev *dev = phy->dev;
+
+	if (IS_ERR_OR_NULL(mlink) || !mlink->offchannel)
+		return;
+
+	dev->drv->vif_link_remove(phy, vif, &vif->bss_conf, mlink);
+	kfree(mlink);
+}

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -777,6 +777,7 @@ struct mt76_vif_link {
 	u8 basic_rates_idx;
 	u8 mcast_rates_idx;
 	u8 beacon_rates_idx;
+	bool offchannel;
 	struct ieee80211_chanctx_conf *ctx;
 	struct mt76_wcid *wcid;
 	struct mt76_vif_data *mvif;
@@ -942,6 +943,7 @@ struct mt76_dev {
 		struct cfg80211_scan_request *req;
 		struct ieee80211_channel *chan;
 		struct ieee80211_vif *vif;
+		struct mt76_vif_link *mlink;
 		struct mt76_phy *phy;
 		int chan_idx;
 	} scan;
@@ -1570,6 +1572,10 @@ int mt76_set_channel(struct mt76_phy *phy, struct cfg80211_chan_def *chandef,
 		     bool offchannel);
 void mt76_scan_work(struct work_struct *work);
 void mt76_abort_scan(struct mt76_dev *dev);
+struct mt76_vif_link *mt76_get_vif_phy_link(struct mt76_phy *phy,
+					    struct ieee80211_vif *vif);
+void mt76_put_vif_phy_link(struct mt76_phy *phy, struct ieee80211_vif *vif,
+			   struct mt76_vif_link *mlink);
 
 /* usb */
 static inline bool mt76u_urb_error(struct urb *urb)

drivers/net/wireless/mediatek/mt76/scan.c

@@ -18,6 +18,7 @@ static void mt76_scan_complete(struct mt76_dev *dev, bool abort)
 
 	if (dev->scan.chan && phy->main_chandef.chan)
 		mt76_set_channel(phy, &phy->main_chandef, false);
+	mt76_put_vif_phy_link(phy, dev->scan.vif, dev->scan.mlink);
 	memset(&dev->scan, 0, sizeof(dev->scan));
 	ieee80211_scan_completed(phy->hw, &info);
 }
@@ -33,7 +34,7 @@ mt76_scan_send_probe(struct mt76_dev *dev, struct cfg80211_ssid *ssid)
 {
 	struct cfg80211_scan_request *req = dev->scan.req;
 	struct ieee80211_vif *vif = dev->scan.vif;
-	struct mt76_vif_link *mvif = (struct mt76_vif_link *)vif->drv_priv;
+	struct mt76_vif_link *mvif = dev->scan.mlink;
 	enum nl80211_band band = dev->scan.chan->band;
 	struct mt76_phy *phy = dev->scan.phy;
 	struct ieee80211_tx_info *info;
@@ -122,6 +123,7 @@ int mt76_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 {
 	struct mt76_phy *phy = hw->priv;
 	struct mt76_dev *dev = phy->dev;
+	struct mt76_vif_link *mlink;
 	int ret = 0;
 
 	if (hw->wiphy->n_radio > 1) {
@@ -137,10 +139,17 @@ int mt76_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		goto out;
 	}
 
+	mlink = mt76_get_vif_phy_link(phy, vif);
+	if (IS_ERR(mlink)) {
+		ret = PTR_ERR(mlink);
+		goto out;
+	}
+
 	memset(&dev->scan, 0, sizeof(dev->scan));
 	dev->scan.req = &req->req;
 	dev->scan.vif = vif;
 	dev->scan.phy = phy;
+	dev->scan.mlink = mlink;
 	ieee80211_queue_delayed_work(dev->phy.hw, &dev->scan_work, 0);
 
 out: