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=1794590917; b=iPXZYCIwX/YOizXlTspQEDAxhBJgT5sRJ8E5L+c+xDWu2KumCrRRGOaSm3bibfmPIdms l/GREuRK0/F6JBMFTX58x3L2UXLDfsbch9I1Dp3sFMVc5LKNPucUJ0li8fvp0akf7Gsm/ JNenJcrhuLq7KGwJNc5CwiVmfoafwmcY9/EYS4tpGYOCeewK7HSaaX8OUhIuTIhAD94AC JQQSo8oJJOy+jGwCe10EThJT+WsQ10BK/n3L7tnExUKSw/7g8DD2HSEtCVv45aNR2NWhd JbHF5SA/Qwf4XLaETyeCjwDYrVSjZwgLTwegVtjnDvwciAR9zmtkYVgzllp9nwyLdNw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590917; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=CEjpqJ7qXSC4PPRUY2iUgQDzTBPn2ej0JbJMZJ83vNE=; b=V3ZiUYlyA0vyodD0073ADh0icogbJBXTxfknSAynb0TvPvm0SkNXVeurksvvFktsqj2E SQ4xOr3jLc0H2+x1CXpCVr5EpEKxnNCBByHvCtLwjGkkIPG6kqO9XFTqeNJJE1Mq2XG5Z pqCDdzOiZDK6iXzeAmQtJ5yohqy4/hkHCswNfPi1fx8k1Ro/sNvp1jmrrqwQm/VWnIl8Y kGpvJIgFXEsXm574sZE01jt9FLhrO5Mn6efYS2ZWKgpySbjImdrBbOuPsIN8uthQul3zM 20yis5cA08c6uItONufneK7NVgIuVdcx51hP2d/pE6zh+DuqLEwoaOUrQV6agf+WA6Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=O9wcRaxc; 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 29AB9606A327; Fri, 13 Nov 2026 17:28:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=O9wcRaxc Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA1251F000C5; Fri, 13 Nov 2026 17:28:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590917; bh=CEjpqJ7qXSC4PPRUY2iUgQDzTBPn2ej0JbJMZJ83vNE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=O9wcRaxcaa1K5rL1umm0CnUYSvJfk9En5iLipvpdfmoQPd/jlHcZzG1rEb0LxRdcT bZxgH/UirDFGzsoI6IsagUFz3Oxoif9DV4xAT1jS/JxulLI9i92IcUgYZGnavZFGog JNGQmMOhe12JvZD9t5zo/9t/p/h/TpFKou+CIVpc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stanislaw Gruszka , Johannes Berg , Sasha Levin Subject: [PATCH 6.12 098/670] wifi: mac80211: queue frames while off-channel Date: Fri, 13 Nov 2026 10:44:22 -0500 Message-ID: <20261113153815.221553516@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Stanislaw Gruszka Signed-off-by: Sasha Levin --- net/mac80211/tx.c | 55 ++++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 27 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 0fad278d8f249..3b01934a6e800 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -276,7 +276,6 @@ 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; @@ -284,23 +283,6 @@ 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 the link below and - * ieee80211_start_scan() for more. - * - * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089 - */ - return TX_DROP; - if (tx->sdata->vif.type == NL80211_IFTYPE_OCB) return TX_CONTINUE; @@ -810,6 +792,33 @@ 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]; @@ -1853,6 +1862,7 @@ 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); @@ -4667,10 +4677,6 @@ 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; @@ -4748,11 +4754,6 @@ 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