Re: rtw89: Did a8188bb7644f change the behaviour for MLO?

[Bitterblue Smith <rtl8821cerfe2@gmail.com>]

On 08/11/2026 03:41, Ping-Ke Shih wrote:
> Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:
>> a8188bb7644f ("wifi: mac80211: change public RX API to use link stations")
>> does this:
>>
>> diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
>> index 397ebbfcac09af..454d876aeb8861 100644
>> --- a/drivers/net/wireless/realtek/rtw89/core.c
>> +++ b/drivers/net/wireless/realtek/rtw89/core.c
>> @@ -3073,10 +3073,8 @@ static void rtw89_vif_rx_stats_iter(void *data, u8 *mac,
>>         struct rtw89_vif *rtwvif = vif_to_rtwvif(vif);
>>         struct rtw89_rx_desc_info *desc_info = iter_data->desc_info;
>>         struct sk_buff *skb = iter_data->skb;
>> -       struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
>>         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
>>         struct rtw89_rx_phy_ppdu *phy_ppdu = iter_data->phy_ppdu;
>> -       bool is_mld = ieee80211_vif_is_mld(vif);
>>         struct ieee80211_bss_conf *bss_conf;
>>         struct rtw89_vif_link *rtwvif_link;
>>         const u8 *bssid = iter_data->bssid;
>> @@ -3110,11 +3108,6 @@ static void rtw89_vif_rx_stats_iter(void *data, u8 *mac,
>>         if (!ether_addr_equal(target_bssid, bssid))
>>                 goto out;
>>
>> -       if (is_mld) {
>> -               rx_status->link_valid = true;
>> -               rx_status->link_id = rtwvif_link->link_id;
>> -       }
>> -
>>         bb = rtw89_get_bb_ctx(rtwdev, rtwvif_link->phy_idx);
>>         pkt_stat = &bb->cur_pkt_stat;
>>
>> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
>> index 7bb4618065b672..cba7cdf61ce8a5 100644
>> --- a/include/net/mac80211.h
>> +++ b/include/net/mac80211.h
>> @@ -5389,14 +5389,18 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw);
>>   * mixed for a single hardware. Must not run concurrently with
>>   * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
>>   *
>> + * For data frames, when hardware has done address translation, a link station
>> + * has to be provided and the frequency information may be skipped.
>> + *
>>   * This function must be called with BHs disabled and RCU read lock
>>   *
>>   * @hw: the hardware this frame came in on
>> - * @sta: the station the frame was received from, or %NULL
>> + * @link_sta: the link station the data frame was received from, or %NULL
>>   * @skb: the buffer to receive, owned by mac80211 after this call
>>   * @list: the destination list
>>   */
>> -void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
>> +void ieee80211_rx_list(struct ieee80211_hw *hw,
>> +                      struct ieee80211_link_sta *link_sta,
>>                        struct sk_buff *skb, struct list_head *list);
>>
>>  /**
>> @@ -5414,14 +5418,18 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
>>   * mixed for a single hardware. Must not run concurrently with
>>   * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
>>   *
>> + * For data frames, when hardware has done address translation, a link station
>> + * has to be provided and the frequency information may be skipped.
>> + *
>>   * This function must be called with BHs disabled.
>>   *
>>   * @hw: the hardware this frame came in on
>> - * @sta: the station the frame was received from, or %NULL
>> + * @link_sta: the link station the data frame was received from, or %NULL
>>   * @skb: the buffer to receive, owned by mac80211 after this call
>>   * @napi: the NAPI context
>>   */
>> -void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
>> +void ieee80211_rx_napi(struct ieee80211_hw *hw,
>> +                      struct ieee80211_link_sta *link_sta,
>>                        struct sk_buff *skb, struct napi_struct *napi);
>>
>>  /**
>> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
>> index 31dc6f83781b1d..0ddd0b8ea12a05 100644
>> --- a/net/mac80211/rx.c
>> +++ b/net/mac80211/rx.c
>> @@ -5556,7 +5556,8 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
>>   * This is the receive path handler. It is called by a low level driver when an
>>   * 802.11 MPDU is received from the hardware.
>>   */
>> -void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
>> +void ieee80211_rx_list(struct ieee80211_hw *hw,
>> +                      struct ieee80211_link_sta *link_pubsta,
>>                        struct sk_buff *skb, struct list_head *list)
>>  {
>>         struct ieee80211_local *local = hw_to_local(hw);
>> @@ -5564,6 +5565,7 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
>>         struct ieee80211_supported_band *sband;
>>         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
>>         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
>> +       struct ieee80211_sta *pubsta;
>>
>>         WARN_ON_ONCE(softirq_count() == 0);
>>
>> @@ -5694,8 +5696,15 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
>>                 }
>>         }
>>
>> -       if (WARN_ON_ONCE(status->link_id >= IEEE80211_LINK_UNSPECIFIED))
>> -               goto drop;
>> +       /* FIXME: Emulate the old driver behaviour for now */
>> +       if (link_pubsta) {
>> +               status->link_valid = 1;
>> +               status->link_id = link_pubsta->link_id;
>> +               pubsta = link_pubsta->sta;
>> +       } else {
>> +               status->link_valid = 0;
>> +               pubsta = NULL;
>> +       }
>>
>>         status->rx_flags = 0;
>>
>> @@ -5727,7 +5736,8 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
>>  }
>>  EXPORT_SYMBOL(ieee80211_rx_list);
>>
>> -void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
>> +void ieee80211_rx_napi(struct ieee80211_hw *hw,
>> +                      struct ieee80211_link_sta *link_pubsta,
>>                        struct sk_buff *skb, struct napi_struct *napi)
>>  {
>>         struct sk_buff *tmp;
>> @@ -5740,7 +5750,7 @@ void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
>>          * receive processing
>>          */
>>         rcu_read_lock();
>> -       ieee80211_rx_list(hw, pubsta, skb, &list);
>> +       ieee80211_rx_list(hw, link_pubsta, skb, &list);
>>         rcu_read_unlock();
>>
>>         if (!napi) {
>>
>> rtw89_core_rx_to_mac80211() calls ieee80211_rx_napi() with link_sta = NULL,
>> so it's not getting the emulated old behaviour in ieee80211_rx_list().
>>
>> Is this something that needs fixing?
> 
> By the comment of link_id field in struct ieee80211_rx_status:
> 
>  * @link_id: id of the link used to receive the packet. Set and used by
>  *	mac80211 internally, it uses @freq set by the driver to identify the
>  *	correct link per vif.
> 
> rtw89 can report proper freq to get link_id back. We tested 7.4-rc and
> things are expected. Did you encounter problems?

No problems here. I can't test MLO, actually. I just noticed this change
while importing the latest patches [1] and thought to ask.

[1] https://github.com/morrownr/rtw89