[PATCH] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[PATCH] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[Jose Ignacio Tornos Martinez]

The driver fails to register with error -22 (EINVAL) due to a cfg80211
validation failure in wiphy_verify_iface_combinations().

Commit 5ef0e8e2653b ("wifi: mt76: mt7996: fix iface combination for
different chipsets") added beacon_int_min_gcd to if_comb_global and
if_comb_global_7992, but these combinations include ADHOC (IBSS)
interface type. This violates a cfg80211 rule from commit 56271da29c52
("cfg80211: simplify netlink socket owner interface deletion") that
explicitly forbids combining ADHOC with beacon_int_min_gcd.

The restriction exists because beacon_int_min_gcd requires static,
predictable beacon intervals to coordinate multiple beaconing interfaces,
but ADHOC interfaces have dynamic beacon intervals that change when
joining different networks, making the GCD constraint unenforceable.

Remove beacon_int_min_gcd from the interface combinations that include
ADHOC because they are not necessary for ADHOC operation. The if_comb
combination (AP/MESH/STA only, without ADHOC) correctly retains
beacon_int_min_gcd for multi-AP coordination.

Fixes: 5ef0e8e2653b ("wifi: mt76: mt7996: fix iface combination for different chipsets")
Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/init.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/init.c b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
index d6f9aa1ab52d..06f764a54405 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
@@ -34,7 +34,6 @@ static const struct ieee80211_iface_combination if_comb_global = {
 			       BIT(NL80211_CHAN_WIDTH_40) |
 			       BIT(NL80211_CHAN_WIDTH_80) |
 			       BIT(NL80211_CHAN_WIDTH_160),
-	.beacon_int_min_gcd = 100,
 };
 
 static const struct ieee80211_iface_combination if_comb_global_7992 = {
@@ -47,7 +46,6 @@ static const struct ieee80211_iface_combination if_comb_global_7992 = {
 			       BIT(NL80211_CHAN_WIDTH_40) |
 			       BIT(NL80211_CHAN_WIDTH_80) |
 			       BIT(NL80211_CHAN_WIDTH_160),
-	.beacon_int_min_gcd = 100,
 };
 
 static const struct ieee80211_iface_limit if_limits[] = {
-- 
2.54.0

Re: [PATCH] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[Johannes Berg]

On Thu, 2026-07-02 at 09:16 +0200, Jose Ignacio Tornos Martinez wrote:
> This violates a cfg80211 rule from commit 56271da29c52
> ("cfg80211: simplify netlink socket owner interface deletion") that

What?

johannes

Re: [PATCH] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[Jose Ignacio Tornos Martinez]

Hi Johannes,

You're absolutely right - I had the wrong commit title. It should be
"cfg80211: disallow beacon_int_min_gcd with IBSS".

I've already sent v2 with the correction.

Thanks for the quick review

Best regards
Jose Ignacio