From af72b5946d493cecced27d0951ea37c1d178601e Mon Sep 17 00:00:00 2001 From: Lachlan Hodges Date: Thu, 27 Aug 2026 15:43:02 +1000 Subject: [PATCH] wifi: mac80211: include TIM bitmap control for buffered S1G mcast traffic Currently when building the S1G TIM element, we only build the bitmap control if we have buffered unicast traffic. Since AID 0 sits within the bitmap control if we have buffered multicast traffic with no buffered unicast traffic the bitmap control won't be emitted and dozing stations will be unaware of buffered multicast. To fix, only exclude the bitmap control byte when we don't have both buffered unicast and multicast traffic. Fixes: ee6360945483 ("wifi: mac80211: support block bitmap S1G TIM encoding") Signed-off-by: Lachlan Hodges Link: https://patch.msgid.link/20260827054302.254124-1-lachlan.hodges@morsemicro.com Signed-off-by: Johannes Berg --- net/mac80211/tx.c | 41 ++++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 19 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 3a1e2c9e1565..3896c7b2c4e5 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -5089,10 +5089,18 @@ static void ieee80211_beacon_add_tim_pvb(struct ps_data *ps, */ static void ieee80211_s1g_beacon_add_tim_pvb(struct ps_data *ps, struct sk_buff *skb, - bool mcast_traffic) + bool mcast_traffic, + bool ucast_traffic) { int blk; + /* + * if no unicast and multicast traffic don't emit a bitmap control + * or pvb + */ + if (!mcast_traffic && !ucast_traffic) + return; + /* * Emit a bitmap control block with a page slice number of 31 and a * page index of 0 which indicates as per IEEE80211-2024 9.4.2.5.1 @@ -5101,6 +5109,10 @@ static void ieee80211_s1g_beacon_add_tim_pvb(struct ps_data *ps, */ skb_put_u8(skb, mcast_traffic | (31 << 1)); + /* If there's no unicast traffic we don't need to include a PVB. */ + if (!ucast_traffic) + return; + /* Emit an encoded block for each non-zero sub-block */ for (blk = 0; blk < IEEE80211_MAX_SUPPORTED_S1G_TIM_BLOCKS; blk++) { u8 blk_bmap = 0; @@ -5182,25 +5194,16 @@ static void __ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata, ps->dtim_bc_mc = mcast_traffic; - if (have_bits) { - if (s1g) - ieee80211_s1g_beacon_add_tim_pvb(ps, skb, - mcast_traffic); - else - ieee80211_beacon_add_tim_pvb(ps, skb, mcast_traffic); + if (s1g) { + ieee80211_s1g_beacon_add_tim_pvb(ps, skb, mcast_traffic, + have_bits); + } else if (have_bits) { + ieee80211_beacon_add_tim_pvb(ps, skb, mcast_traffic); } else { - /* - * If there is no buffered unicast traffic for an S1G - * interface, we can exclude the bitmap control. This is in - * contrast to other phy types as they do include the bitmap - * control and pvb even when there is no buffered traffic. - */ - if (!s1g) { - /* Bitmap control */ - skb_put_u8(skb, mcast_traffic); - /* Part Virt Bitmap */ - skb_put_u8(skb, 0); - } + /* Bitmap control */ + skb_put_u8(skb, mcast_traffic); + /* Part Virt Bitmap */ + skb_put_u8(skb, 0); } tim->datalen = skb_tail_pointer(skb) - tim->data;