[PATCH v2] wifi: mt76: mt7925: fix AMPDU state handling in mt7925_tx_check_aggr

[Sean Wang]

On Thu, Nov 27, 2025 at 1:55 AM Quan Zhou <quan.zhou at mediatek.com> wrote:
>
> Previously, the AMPDU state bit for a given TID was set before attempting
> to start a BA session, which could result in the AMPDU state being marked
> active even if ieee80211_start_tx_ba_session() failed. This patch changes
> the logic to only set the AMPDU state bit after successfully starting a BA
> session, ensuring proper synchronization between AMPDU state and BA session
> status.
>
> This fixes potential issues with aggregation state tracking and improves
> compatibility with mac80211 BA session management.
>
> Fixes: 44eb173bdd4f ("wifi: mt76: mt7925: add link handling in mt7925_txwi_free")
> Cc: stable at vger.kernel.org
>
> Signed-off-by: Quan Zhou <quan.zhou at mediatek.com>
> ---
> v2: modify to avoid weakening atomicity
> ---
>  drivers/net/wireless/mediatek/mt76/mt7925/mac.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mac.c b/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
> index 871b67101976..5e5b1df78633 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
> @@ -881,8 +881,10 @@ static void mt7925_tx_check_aggr(struct ieee80211_sta *sta, struct sk_buff *skb,
>         else
>                 mlink = &msta->deflink;
>
> -       if (!test_and_set_bit(tid, &mlink->wcid.ampdu_state))
> -               ieee80211_start_tx_ba_session(sta, tid, 0);
> +       if (!test_and_set_bit(tid, &mlink->wcid.ampdu_state)) {
> +               if (ieee80211_start_tx_ba_session(sta, tid, 0))
> +                       clear_bit(tid, &mlink->wcid.ampdu_state);
> +       }
>  }
>

Reviewed-by: Sean Wang <sean.wang at mediatek.com>

>  static bool
> --
> 2.45.2
>
>