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wireless: add check of field VHT Extended NSS BW Capable for 160/80+80 MHz setting

PATCH Superseded Wen Gong 2 participants 3 messages May 20, 2021 – May 21, 2021

Subsystems (2)
802.11 (including cfg80211/NL80211) Qualcomm Atheros ATH11K wireless driver

v1 of 3 Superseded Latest is v3 →

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Wen Gong

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#0 lore raw

PATCH 1/1 wireless: add check of field VHT Extended NSS BW Capable for 160/80+80 MHz setting

Table 9-251—Supported VHT-MCS and NSS Set subfields, it has subfield VHT Extended NSS BW Capable, its definition is:
Indicates whether the STA is capable of interpreting the Extended NSS BW Support subfield of the VHT Capabilities Information field.

This patch is to add check for the subfield.

Signed-off-by Wen Gong <[email protected]>
---
 net/wireless/chan.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
net/wireless/chan.c +5 -3
index 285b8076054b..f7f86bd75cc0 100644
@@ -942,7 +942,7 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 	struct ieee80211_sta_vht_cap *vht_cap;
 	struct ieee80211_edmg *edmg_cap;
 	u32 width, control_freq, cap;
-	bool support_80_80 = false;
+	bool ext_nss_cap, support_80_80 = false;
 
 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 		return false;

@@ -950,6 +950,7 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
 	edmg_cap = &wiphy->bands[chandef->chan->band]->edmg_cap;
+	ext_nss_cap = vht_cap->vht_mcs.tx_highest & IEEE80211_VHT_EXT_NSS_BW_CAPABLE;
 
 	if (edmg_cap->channels &&
 	    !cfg80211_edmg_usable(wiphy,

@@ -1015,7 +1016,8 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 			(cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ) ||
 			(cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
 			 cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) ||
-			u32_get_bits(cap, IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) > 1;
+			(ext_nss_cap &&
+			 u32_get_bits(cap, IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) > 1);
 		if (chandef->chan->band != NL80211_BAND_6GHZ && !support_80_80)
 			return false;
 		fallthrough;

@@ -1037,7 +1039,7 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ &&
-		    !(vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))
+		    !(ext_nss_cap && vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))
 			return false;
 		break;
 	default:
Signature · 1 line
2.31.1
#1 lore raw
Quoted 6 lines · Wen Gong

Table 9-251—Supported VHT-MCS and NSS Set subfields, it has subfield VHT Extended NSS BW Capable, its definition is:
Indicates whether the STA is capable of interpreting the Extended NSS BW Support subfield of the VHT Capabilities Information field.

This patch is to add check for the subfield.

Almost looks good to me, but...

Quoted 9 lines
Signed-off-by Wen Gong <[email protected]>
---
  net/wireless/chan.c | 8 +++++---
  1 file changed, 5 insertions(+), 3 deletions(-)
net/wireless/chan.c +0 -0
index 285b8076054b..f7f86bd75cc0 100644

[...]

net/wireless/chan.c bool cfg80211_chandef_usable(struct wiphy *wiphy, · line 1042

Quoted 6 lines
net/wireless/chan.c +1 -1
@@ -1037,7 +1039,7 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
  		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
  		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
  		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ &&
-		    !(vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))
+		    !(ext_nss_cap && vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))

you should not mix logical and binary operators so add braces around the binary operation here.

Regards,
Arend

Quoted 4 lines
net/wireless/chan.c +0 -0
  			return false;
  		break;
  	default:
author
#2 lore raw
Quoted 22 lines · Arend van Spriel
Quoted 6 lines · Wen Gong

Table 9-251—Supported VHT-MCS and NSS Set subfields, it has subfield VHT Extended NSS BW Capable, its definition is:
Indicates whether the STA is capable of interpreting the Extended NSS BW Support subfield of the VHT Capabilities Information field.

This patch is to add check for the subfield.

Almost looks good to me, but...

Quoted 9 lines
Signed-off-by Wen Gong <[email protected]>
---
  net/wireless/chan.c | 8 +++++---
  1 file changed, 5 insertions(+), 3 deletions(-)
net/wireless/chan.c +0 -0
index 285b8076054b..f7f86bd75cc0 100644

[...]

Quoted 11 lines

net/wireless/chan.c bool cfg80211_chandef_usable(struct wiphy · line 1044

Quoted 8 lines
net/wireless/chan.c +1 -1
@@ -1037,7 +1039,7 @@ bool cfg80211_chandef_usable(struct wiphy 
 *wiphy,
  		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
  		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
  		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ &&
-		    !(vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))
+		    !(ext_nss_cap && vht_cap->cap & 
 IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))

you should not mix logical and binary operators so add braces around the binary operation here.

priority of & is higher than &&, so it not need to add braces here. however, i have sent patch v2 which added the braces.
https://lore.kernel.org/linux-wireless/[email protected]/T/#u

Quoted 8 lines

Regards,
Arend

Quoted 4 lines
net/wireless/chan.c +0 -0
  			return false;

break;
default: