[PATCH 0/2] wifi: mt76: mt7996: clamp beamforming NSS

[PATCH 0/2] wifi: mt76: mt7996: clamp beamforming NSS

[Jiale Yao]

From: Jiale Yao <jiale.yao@example.com>

The mt7996 beamforming configuration converts a peer maximum NSS to a
zero-based column count.  A peer may report no receive streams for a
VHT, HE, or EHT MCS range.  Decrementing that zero value underflows and
can send an invalid beamforming configuration to firmware.

Patch 1 fixes the shared VHT and HE MCS-map conversion.  Patch 2 fixes
the corresponding EHT conversions for 80, 160, and 320 MHz operation.

The series was checked with scripts/checkpatch.pl, and each patch was
checked for application against the common base.

Jiale Yao (2):
  wifi: mt76: mt7996: clamp VHT/HE beamforming NSS
  wifi: mt76: mt7996: clamp EHT beamforming NSS

 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

-- 
2.34.1

[PATCH 1/2] wifi: mt76: mt7996: clamp VHT/HE beamforming NSS

[Jiale Yao]

From: Jiale Yao <jiale.yao@example.com>

A peer can advertise a VHT or HE MCS map with no supported
spatial streams.  In that case mt7996_mcu_get_sta_nss() decrements
zero and produces 255 for the beamforming configuration.

Return zero when the MCS map has no supported streams.

Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Jiale Yao <jiale.yao@example.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index cd7587ce5b8a..e6243dd33c31 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -120,7 +120,7 @@ mt7996_mcu_get_sta_nss(u16 mcs_map)
 			break;
 	}
 
-	return nss - 1;
+	return nss ? nss - 1 : 0;
 }
 
 static void
-- 
2.34.1

[PATCH 2/2] wifi: mt76: mt7996: clamp EHT beamforming NSS

[Jiale Yao]

From: Jiale Yao <jiale.yao@example.com>

An EHT peer can advertise zero receive spatial streams for an MCS
range.  The beamforming setup decrements that value, causing an
underflow and sending an invalid column count to firmware.

Clamp the converted NSS value to zero for 80, 160, and 320 MHz
beamforming configurations.

Fixes: ba01944adee9 ("wifi: mt76: mt7996: add EHT beamforming support")
Signed-off-by: Jiale Yao <jiale.yao@example.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index e6243dd33c31..29b67248fad7 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -1969,7 +1969,7 @@ mt7996_mcu_sta_bfer_eht(struct ieee80211_link_sta *link_sta,
 	struct ieee80211_eht_cap_elem_fixed *pe = &pc->eht_cap_elem;
 	struct ieee80211_eht_mcs_nss_supp *eht_nss = &pc->eht_mcs_nss_supp;
 	u8 nss_mcs = u8_get_bits(eht_nss->bw._80.rx_tx_mcs9_max_nss,
-				 IEEE80211_EHT_MCS_NSS_RX) - 1;
+				 IEEE80211_EHT_MCS_NSS_RX);
 	const struct ieee80211_eht_cap_elem_fixed *ve;
 	const struct ieee80211_sta_eht_cap *vc;
 	u8 snd_dim, sts;
@@ -1988,6 +1988,7 @@ mt7996_mcu_sta_bfer_eht(struct ieee80211_link_sta *link_sta,
 	snd_dim = EHT_PHY(CAP2_SOUNDING_DIM_80MHZ_MASK, ve->phy_cap_info[2]);
 	sts = EHT_PHY(CAP0_BEAMFORMEE_SS_80MHZ_MASK, pe->phy_cap_info[0]) +
 	      (EHT_PHY(CAP1_BEAMFORMEE_SS_80MHZ_MASK, pe->phy_cap_info[1]) << 1);
+	nss_mcs = nss_mcs ? nss_mcs - 1 : 0;
 	bf->nrow = min_t(u8, snd_dim, sts);
 	bf->ncol = min_t(u8, nss_mcs, bf->nrow);
 	bf->ibf_ncol = explicit ? min_t(u8, MT7996_IBF_MAX_NC, bf->ncol) :
@@ -2001,7 +2002,8 @@ mt7996_mcu_sta_bfer_eht(struct ieee80211_link_sta *link_sta,
 		snd_dim = EHT_PHY(CAP2_SOUNDING_DIM_160MHZ_MASK, ve->phy_cap_info[2]);
 		sts = EHT_PHY(CAP1_BEAMFORMEE_SS_160MHZ_MASK, pe->phy_cap_info[1]);
 		nss_mcs = u8_get_bits(eht_nss->bw._160.rx_tx_mcs9_max_nss,
-				      IEEE80211_EHT_MCS_NSS_RX) - 1;
+				      IEEE80211_EHT_MCS_NSS_RX);
+		nss_mcs = nss_mcs ? nss_mcs - 1 : 0;
 
 		bf->nrow_gt_bw80 = min_t(u8, snd_dim, sts);
 		bf->ncol_gt_bw80 = nss_mcs;
@@ -2012,7 +2014,8 @@ mt7996_mcu_sta_bfer_eht(struct ieee80211_link_sta *link_sta,
 				   ve->phy_cap_info[3]) << 1);
 		sts = EHT_PHY(CAP1_BEAMFORMEE_SS_320MHZ_MASK, pe->phy_cap_info[1]);
 		nss_mcs = u8_get_bits(eht_nss->bw._320.rx_tx_mcs9_max_nss,
-				      IEEE80211_EHT_MCS_NSS_RX) - 1;
+				      IEEE80211_EHT_MCS_NSS_RX);
+		nss_mcs = nss_mcs ? nss_mcs - 1 : 0;
 
 		bf->nrow_gt_bw80 = min_t(u8, snd_dim, sts) << 4;
 		bf->ncol_gt_bw80 = nss_mcs << 4;
-- 
2.34.1

[PATCH 1/2] wifi: mt76: mt7996: clamp VHT/HE beamforming NSS

[Jiale Yao]

A peer can advertise a VHT or HE MCS map with no supported
spatial streams.  In that case mt7996_mcu_get_sta_nss() decrements
zero and produces 255 for the beamforming configuration.

Return zero when the MCS map has no supported streams.

Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index cd7587ce5b8a..e6243dd33c31 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -120,7 +120,7 @@ mt7996_mcu_get_sta_nss(u16 mcs_map)
 			break;
 	}
 
-	return nss - 1;
+	return nss ? nss - 1 : 0;
 }
 
 static void
-- 
2.34.1