mt76: fix association failure on kernels without wiphy->n_radio - #22
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mt76: fix association failure on kernels without wiphy->n_radio#22antonionesta wants to merge 1 commit into
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Commit fe503c3 ("mt7902e: Backport down to 6.6") wrapped the n_radio == 0 fast path in mt76_vif_phy() in a version guard, because wiphy->n_radio does not exist on older kernels. The guard removed the fast path instead of preserving its behaviour, so on any kernel below the guarded version mt76_vif_phy() falls through to the chanctx lookup. That lookup is never valid for mt792x. The MT7902 firmware does not advertise MT792x_FW_CAP_CNM, so mt792x_get_mac80211_ops() clears ops->assign_vif_chanctx and mlink->ctx stays NULL forever. mt76_vif_phy() therefore returns NULL, mt76_sta_state() bails out with -EINVAL, and every association attempt fails with: wlan0: failed to insert STA entry for the AP (error -22) mt76_get_txpower() is broken by the same path and stops reporting TX power. Even with a CNM-capable firmware the fall-through would be wrong: mt792x sets hw->chanctx_data_size to sizeof(struct mt792x_chanctx), whose first member is a struct mt792x_bss_conf pointer, so the struct mt76_chanctx cast would be a type confusion. This driver never registers more than one radio, so the n_radio == 0 fast path always applies. Return hw->priv unconditionally on kernels lacking wiphy->n_radio, mirroring the #else pattern already used for mt76_get_survey() in the same commit. Tested on 6.12.100+deb13-amd64: association completes and the link reaches HE-MCS 11 rates. Fixes: fe503c3 ("mt7902e: Backport down to 6.6") Signed-off-by: Antonio Nesta <antodj94@gmail.com>
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Commit fe503c3 ("mt7902e: Backport down to 6.6") wrapped the n_radio == 0 fast path in mt76_vif_phy() in a version guard, because wiphy->n_radio does not exist on older kernels. The guard removed the fast path instead of preserving its behaviour, so on any kernel below the guarded version mt76_vif_phy() falls through to the chanctx lookup.
That lookup is never valid for mt792x. The MT7902 firmware does not advertise MT792x_FW_CAP_CNM, so mt792x_get_mac80211_ops() clears ops->assign_vif_chanctx and mlink->ctx stays NULL forever. mt76_vif_phy() therefore returns NULL, mt76_sta_state() bails out with -EINVAL, and every association attempt fails with:
wlan0: failed to insert STA entry for the AP (error -22)
mt76_get_txpower() is broken by the same path and stops reporting TX power.
Even with a CNM-capable firmware the fall-through would be wrong: mt792x sets hw->chanctx_data_size to sizeof(struct mt792x_chanctx), whose first member is a struct mt792x_bss_conf pointer, so the struct mt76_chanctx cast would be a type confusion.
This driver never registers more than one radio, so the n_radio == 0 fast path always applies. Return hw->priv unconditionally on kernels lacking wiphy->n_radio, mirroring the #else pattern already used for mt76_get_survey() in the same commit.
Tested on 6.12.100+deb13-amd64: association completes and the link reaches HE-MCS 11 rates.
Fixes: fe503c3 ("mt7902e: Backport down to 6.6")