Commit 28d519d0 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Felix Fietkau
Browse files

wifi: mt76: Move RCU section in mt7996_mcu_add_rate_ctrl_fixed() 



Since mt7996_mcu_set_fixed_field() can't be executed in a RCU critical
section, move RCU section in mt7996_mcu_add_rate_ctrl_fixed() and run
mt7996_mcu_set_fixed_field() in non-atomic context. This is a
preliminary patch to fix a 'sleep while atomic' issue in
mt7996_mac_sta_rc_work().

Fixes: 0762bdd3 ("wifi: mt76: mt7996: rework mt7996_mac_sta_rc_work to support MLO")
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250605-mt7996-sleep-while-atomic-v1-3-d46d15f9203c@kernel.org


Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent c772cd72

drivers/net/wireless/mediatek/mt76/mt7996/mcu.c

+57 −29
Original line number Diff line number Diff line
@@ -1977,51 +1977,74 @@ int mt7996_mcu_set_fixed_field(struct mt7996_dev *dev, struct mt7996_sta *msta, 
}



static int

mt7996_mcu_add_rate_ctrl_fixed(struct mt7996_dev *dev,

			       struct ieee80211_link_sta *link_sta,

			       struct mt7996_vif_link *link,

			       struct mt7996_sta_link *msta_link,

			       u8 link_id)

mt7996_mcu_add_rate_ctrl_fixed(struct mt7996_dev *dev, struct mt7996_sta *msta,

			       struct ieee80211_vif *vif, u8 link_id)

{

	struct cfg80211_chan_def *chandef = &link->phy->mt76->chandef;

	struct cfg80211_bitrate_mask *mask = &link->bitrate_mask;

	enum nl80211_band band = chandef->chan->band;

	struct mt7996_sta *msta = msta_link->sta;

	struct ieee80211_link_sta *link_sta;

	struct cfg80211_bitrate_mask mask;

	struct mt7996_sta_link *msta_link;

	struct mt7996_vif_link *link;

	struct sta_phy_uni phy = {};

	int ret, nrates = 0;

	struct ieee80211_sta *sta;

	int ret, nrates = 0, idx;

	enum nl80211_band band;

	bool has_he;



#define __sta_phy_bitrate_mask_check(_mcs, _gi, _ht, _he)			\

	do {									\

		u8 i, gi = mask->control[band]._gi;				\

		u8 i, gi = mask.control[band]._gi;				\

		gi = (_he) ? gi : gi == NL80211_TXRATE_FORCE_SGI;		\

		phy.sgi = gi;							\

		phy.he_ltf = mask->control[band].he_ltf;			\

		for (i = 0; i < ARRAY_SIZE(mask->control[band]._mcs); i++) {	\

			if (!mask->control[band]._mcs[i])			\

		phy.he_ltf = mask.control[band].he_ltf;				\

		for (i = 0; i < ARRAY_SIZE(mask.control[band]._mcs); i++) {	\

			if (!mask.control[band]._mcs[i])			\

				continue;					\

			nrates += hweight16(mask->control[band]._mcs[i]);	\

			phy.mcs = ffs(mask->control[band]._mcs[i]) - 1;		\

			nrates += hweight16(mask.control[band]._mcs[i]);	\

			phy.mcs = ffs(mask.control[band]._mcs[i]) - 1;		\

			if (_ht)						\

				phy.mcs += 8 * i;				\

		}								\

	} while (0)



	if (link_sta->he_cap.has_he) {

	rcu_read_lock();



	link = mt7996_vif_link(dev, vif, link_id);

	if (!link)

		goto error_unlock;



	msta_link = rcu_dereference(msta->link[link_id]);

	if (!msta_link)

		goto error_unlock;



	sta = wcid_to_sta(&msta_link->wcid);

	link_sta = rcu_dereference(sta->link[link_id]);

	if (!link_sta)

		goto error_unlock;



	band = link->phy->mt76->chandef.chan->band;

	has_he = link_sta->he_cap.has_he;

	mask = link->bitrate_mask;

	idx = msta_link->wcid.idx;



	if (has_he) {

		__sta_phy_bitrate_mask_check(he_mcs, he_gi, 0, 1);

	} else if (link_sta->vht_cap.vht_supported) {

		__sta_phy_bitrate_mask_check(vht_mcs, gi, 0, 0);

	} else if (link_sta->ht_cap.ht_supported) {

		__sta_phy_bitrate_mask_check(ht_mcs, gi, 1, 0);

	} else {

		nrates = hweight32(mask->control[band].legacy);

		phy.mcs = ffs(mask->control[band].legacy) - 1;

		nrates = hweight32(mask.control[band].legacy);

		phy.mcs = ffs(mask.control[band].legacy) - 1;

	}



	rcu_read_unlock();



#undef __sta_phy_bitrate_mask_check



	/* fall back to auto rate control */

	if (mask->control[band].gi == NL80211_TXRATE_DEFAULT_GI &&

	    mask->control[band].he_gi == GENMASK(7, 0) &&

	    mask->control[band].he_ltf == GENMASK(7, 0) &&

	if (mask.control[band].gi == NL80211_TXRATE_DEFAULT_GI &&

	    mask.control[band].he_gi == GENMASK(7, 0) &&

	    mask.control[band].he_ltf == GENMASK(7, 0) &&

	    nrates != 1)

		return 0;
@@ -2034,16 +2057,16 @@ mt7996_mcu_add_rate_ctrl_fixed(struct mt7996_dev *dev, 
	}



	/* fixed GI */

	if (mask->control[band].gi != NL80211_TXRATE_DEFAULT_GI ||

	    mask->control[band].he_gi != GENMASK(7, 0)) {

	if (mask.control[band].gi != NL80211_TXRATE_DEFAULT_GI ||

	    mask.control[band].he_gi != GENMASK(7, 0)) {

		u32 addr;



		/* firmware updates only TXCMD but doesn't take WTBL into

		 * account, so driver should update here to reflect the

		 * actual txrate hardware sends out.

		 */

		addr = mt7996_mac_wtbl_lmac_addr(dev, msta_link->wcid.idx, 7);

		if (link_sta->he_cap.has_he)

		addr = mt7996_mac_wtbl_lmac_addr(dev, idx, 7);

		if (has_he)

			mt76_rmw_field(dev, addr, GENMASK(31, 24), phy.sgi);

		else

			mt76_rmw_field(dev, addr, GENMASK(15, 12), phy.sgi);
@@ -2055,7 +2078,7 @@ mt7996_mcu_add_rate_ctrl_fixed(struct mt7996_dev *dev, 
	}



	/* fixed HE_LTF */

	if (mask->control[band].he_ltf != GENMASK(7, 0)) {

	if (mask.control[band].he_ltf != GENMASK(7, 0)) {

		ret = mt7996_mcu_set_fixed_field(dev, msta, &phy, link_id,

						 RATE_PARAM_FIXED_HE_LTF);

		if (ret)
@@ -2063,6 +2086,11 @@ mt7996_mcu_add_rate_ctrl_fixed(struct mt7996_dev *dev, 
	}



	return 0;



error_unlock:

	rcu_read_unlock();



	return -ENODEV;

}



static void
@@ -2181,6 +2209,7 @@ int mt7996_mcu_add_rate_ctrl(struct mt7996_dev *dev, 
			     struct mt7996_sta_link *msta_link,

			     u8 link_id, bool changed)

{

	struct mt7996_sta *msta = msta_link->sta;

	struct sk_buff *skb;

	int ret;
@@ -2207,8 +2236,7 @@ int mt7996_mcu_add_rate_ctrl(struct mt7996_dev *dev, 
	if (ret)

		return ret;



	return mt7996_mcu_add_rate_ctrl_fixed(dev, link_sta, link, msta_link,

					      link_id);

	return mt7996_mcu_add_rate_ctrl_fixed(dev, msta, vif, link_id);

}



static int