[PATCH v2] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[PATCH v2] 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: disallow beacon_int_min_gcd with IBSS") 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>
---
v2: Fix commit 56271da29c52 title reference from "cfg80211: simplify
    netlink socket owner interface deletion" to "cfg80211: disallow
    beacon_int_min_gcd with IBSS"
v1: https://lore.kernel.org/all/20260702071647.667539-1-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 v2] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[Jose Ignacio Tornos Martinez]

Hi Felix, Lorenzo,

Just a gentle ping on this patch when you have a chance to take a look.

It fixes a device registration failure (-EINVAL) for mt7996/mt7992 devices
introduced by commit 5ef0e8e2653b. Without this fix the device is completely
unusable, as cfg80211 validates all advertised interface combinations at
registration time and rejects the entire driver.

Please let me know if there is anything I should improve or change.

Thank you for your time

Best regards,
Jose Ignacio

Re: [PATCH v2] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[Alex Gavin]

On 7/19/26 23:04, Jose Ignacio Tornos Martinez wrote:
> Hi Felix, Lorenzo,
> 
> Just a gentle ping on this patch when you have a chance to take a look.
> 
> It fixes a device registration failure (-EINVAL) for mt7996/mt7992 devices
> introduced by commit 5ef0e8e2653b. Without this fix the device is completely
> unusable, as cfg80211 validates all advertised interface combinations at
> registration time and rejects the entire driver.
> 
> Please let me know if there is anything I should improve or change.
> 
> Thank you for your time
> 
> Best regards,
> Jose Ignacio
> 

This patch fixes driver initialization in my testing. I had previously 
used this patch [1] from OpenWRT's tree as a workaround. I have not done 
any testing with IBSS/ADHOC interfaces, though.


Best,

Alex

[1] 
https://github.com/openwrt/openwrt/blob/main/package/kernel/mac80211/patches/subsys/220-allow-ibss-mixed.patch

Re: [PATCH v2] wifi: mt76: mt7996: remove beacon_int_min_gcd from ADHOC interface combinations

[Alex Gavin]

On 7/20/26 09:17, Alex Gavin wrote:
> On 7/19/26 23:04, Jose Ignacio Tornos Martinez wrote:
>> Hi Felix, Lorenzo,
>>
>> Just a gentle ping on this patch when you have a chance to take a look.
>>
>> It fixes a device registration failure (-EINVAL) for mt7996/mt7992 
>> devices
>> introduced by commit 5ef0e8e2653b. Without this fix the device is 
>> completely
>> unusable, as cfg80211 validates all advertised interface combinations at
>> registration time and rejects the entire driver.
>>
>> Please let me know if there is anything I should improve or change.
>>
>> Thank you for your time
>>
>> Best regards,
>> Jose Ignacio
>>
> 
> This patch fixes driver initialization in my testing. I had previously 
> used this patch [1] from OpenWRT's tree as a workaround. I have not done 
> any testing with IBSS/ADHOC interfaces, though.
> 
> 
> Best,
> 
> Alex
> 
> [1] https://github.com/openwrt/openwrt/blob/main/package/kernel/ 
> mac80211/patches/subsys/220-allow-ibss-mixed.patch
> 

Tested-by: Alex Gavin <alex.gavin@candelatech.com>