From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794281232; b=lPRYEoU6zPCB6z2k9lZJylIAC6eae3WzuHL7DyR35puebBPnzs67QgkpYC3grS/vUy4b VUyD4MKq1FIJ89DYclu4L6+TFh5UdA0kD2M2TGjoYu1vHzg4IRleLkT8apLj9+Rxhqfzl nIpZND8To2dLn3TVaKz2yO5jzvBDG2q4T+dQm/sofvpyk+sYvSlp9UMI/tE5HmTyLwm/L ArDSObyol1sGu0omJOm80TxQERQNGThRObrxgk6spR53ugv6JgWKGxM/ImdH+xiQizjxt yqbdaJLvlr412Js7bQazvY7NtG7uNYWSEcMZCe6dTC8/v8DDgbD7exohaYgDfNc9cgA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794281232; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=9AvXbhAHvbIJydkc7wESiwVHrCSozIEixPr0a6MRCKU=; b=m0flt+GHJmsppt4YNzDJtoxK4P+Kd/8ygSSFuZRZqMY888q2ZLABUfYX5l8gTjygF0qR DiR0pNGYw7MWg4ddYr4+mqkvRtzxxNfbZRYhnZzvxltAEYpMBwXFTzVBygO22HBOzr/P8 HOr1H3e+wn/c7+8t6RHL59ottfl0L5AoJHQ5HI+w3KIJRHYAzcOpD0WCQDG9EudxZDzEz BTGxHTgQYOKO8ltSTjWIFlilGT3fzuIJpGm8ZNh68txmj1Ys652tyceFgeoO+ElExX5lv rDNG4jQGm8oEx7wq4Jy3B4PODwdWDNMMpXoLp8ZJ/p9avE6ifGAk3M9guIA5FSaKuMA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aozM+Nih; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 98FD1606A325 for ; Tue, 10 Nov 2026 03:27:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aozM+Nih Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C7FC1F008A1; Tue, 10 Nov 2026 03:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794281231; bh=9AvXbhAHvbIJydkc7wESiwVHrCSozIEixPr0a6MRCKU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aozM+NihZY5OPcf8job308tNgSAnBpRH8TQ5K6hUHmfPIje1imwTN5Zp6aPeVtVzF bfsGqRif+kBSo6M46ElrUaAEIbPn7pmY622MLDpTEfbEdJ1YGwoQE1I3mAc8csmbEP SBaDtSfq7GwsQDgD2ZYqSSpB/bXnGkPm4th+eB7ctj+I2GZY9qTeuYFovz6/CRxUDB RHr2TAC0qYlDoVZfTBz9gcR+MWnCuJgtiukBwPUEfp19SBq6Kaux6IHbvmrkLWpXVI fERvCTwINwjxlY9plwyWfN1mWUDzmALAIm/MSrMgxxhGLwT+9Ar3weiOuA98BzZUu0 HJ8jPQIbC/TSg== From: Sasha Levin To: stable@vger.kernel.org Cc: Stanislaw Gruszka , Johannes Berg , Sasha Levin Subject: [PATCH 6.6.y 2/2] wifi: mac80211: queue frames while off-channel Date: Mon, 9 Nov 2026 22:27:09 -0500 Message-ID: <20261110032703.180401-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261110032703.180401-1-sashal@kernel.org> References: <20261107052845-failed-6.6-13e51269b665@kernel.org> <20261110032703.180401-1-sashal@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Stanislaw Gruszka [ Upstream commit 13e51269b6656768dc595ed6025e4974f2026543 ] Drivers without FAST_XMIT and hardware scan support currently drop TX frames during software scanning while being off-channel. This happens in ieee80211_tx_h_check_assoc() before frames reach internal TX queue. Move the off-channel check to invoke_tx_handlers_late(), after ieee80211_queue_skb(). Frames can then remain queued and be transmitted when the interface returns on-channel. This how TX works currently when code goes via ieee80211_xmit_fast() path. Below is rt2x00 driver ping output example while scanning, before and after the fix. After the fix, packets are no longer lost. Some have increased latency, what is expected behavior. BEFORE: 64 bytes from 192.168.0.1: icmp_seq=29 ttl=64 time=3.61 ms 64 bytes from 192.168.0.1: icmp_seq=31 ttl=64 time=3.33 ms # Missed 30 64 bytes from 192.168.0.1: icmp_seq=32 ttl=64 time=4.03 ms 64 bytes from 192.168.0.1: icmp_seq=34 ttl=64 time=3.10 ms # Missed 33 64 bytes from 192.168.0.1: icmp_seq=36 ttl=64 time=3.04 ms # Missed 35 64 bytes from 192.168.0.1: icmp_seq=38 ttl=64 time=3.05 ms # Missed 37 64 bytes from 192.168.0.1: icmp_seq=40 ttl=64 time=4.14 ms # Missed 39 64 bytes from 192.168.0.1: icmp_seq=41 ttl=64 time=4.50 ms AFTER: 64 bytes from 192.168.0.1: icmp_seq=29 ttl=64 time=3.40 ms 64 bytes from 192.168.0.1: icmp_seq=30 ttl=64 time=6.10 ms 64 bytes from 192.168.0.1: icmp_seq=31 ttl=64 time=4.69 ms 64 bytes from 192.168.0.1: icmp_seq=32 ttl=64 time=4.49 ms 64 bytes from 192.168.0.1: icmp_seq=33 ttl=64 time=148 ms 64 bytes from 192.168.0.1: icmp_seq=34 ttl=64 time=6.83 ms 64 bytes from 192.168.0.1: icmp_seq=35 ttl=64 time=8.66 ms 64 bytes from 192.168.0.1: icmp_seq=36 ttl=64 time=13.0 ms 64 bytes from 192.168.0.1: icmp_seq=37 ttl=64 time=4.78 ms 64 bytes from 192.168.0.1: icmp_seq=38 ttl=64 time=3.85 ms Cc: Signed-off-by: Stanislaw Gruszka Link: https://patch.msgid.link/20260908124651.2995-1-stf_xl@wp.pl Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/mac80211/tx.c | 52 +++++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 24 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 14513d4fe6329..c0e9ed8ec1d19 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -283,7 +283,6 @@ ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx) static ieee80211_tx_result debug_noinline ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx) { - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); bool assoc = false; @@ -291,20 +290,6 @@ ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx) if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) return TX_CONTINUE; - if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) && - test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) && - !ieee80211_is_probe_req(hdr->frame_control) && - !ieee80211_is_any_nullfunc(hdr->frame_control)) - /* - * When software scanning only nullfunc frames (to notify - * the sleep state to the AP) and probe requests (for the - * active scan) are allowed, all other frames should not be - * sent and we should not get here, but if we do - * nonetheless, drop them to avoid sending them - * off-channel. See __ieee80211_start_scan() for more. - */ - return TX_DROP; - if (tx->sdata->vif.type == NL80211_IFTYPE_OCB) return TX_CONTINUE; @@ -814,6 +799,33 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx) return TX_CONTINUE; } +static ieee80211_tx_result debug_noinline +ieee80211_tx_h_check_offchannel(struct ieee80211_tx_data *tx) +{ + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); + + if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) + return TX_CONTINUE; + + if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) && + test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) && + !ieee80211_is_probe_req(hdr->frame_control) && + !ieee80211_is_any_nullfunc(hdr->frame_control)) { + /* + * When software scanning only nullfunc frames (to notify + * the sleep state to the AP) and probe requests (for the + * active scan) are allowed, all other frames should not be + * sent and we should not get here, but if we do + * nonetheless, drop them to avoid sending them + * off-channel. See __ieee80211_start_scan() for more. + */ + return TX_DROP; + } + + return TX_CONTINUE; +} + static __le16 ieee80211_tx_next_seq(struct sta_info *sta, int tid) { u16 *seq = &sta->tid_seq[tid]; @@ -1866,6 +1878,7 @@ static int invoke_tx_handlers_late(struct ieee80211_tx_data *tx) goto txh_done; } + CALL_TXH(ieee80211_tx_h_check_offchannel); CALL_TXH(ieee80211_tx_h_michael_mic_add); CALL_TXH(ieee80211_tx_h_sequence); CALL_TXH(ieee80211_tx_h_fragment); @@ -4632,10 +4645,6 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, queue = ieee80211_select_queue(sdata, sta, skb); skb_set_queue_mapping(skb, queue); - if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)) && - test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) - goto out_free; - skb = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) return; @@ -4713,11 +4722,6 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, ieee80211_tpt_led_trig_tx(local, len); ieee80211_tx_8023(sdata, skb, sta, false); - - return; - -out_free: - kfree_skb(skb); } static bool ieee80211_check_mcast_offload(struct ieee80211_sub_if_data *sdata, -- 2.53.0