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=1794590069; b=jDq4HJEuZKdNES3WCx1h4hLpK9yNzc00NLZyV9jK3akUacDbfkII2qMqYuyBlRp7K/jU M6vrjwTLBNicHeM+cAKJ6hNVuR+rVXSIuv2xn7v+iFhB6kK2pw/y2hX6b4PwWGt/izbnx spj0pedBv2cnwJ5xXOhp7VP0WgWcSJugYndLYdzkj4qj9oysfWbL1zzuS1RnRzg44WP9s VM97ueMvpzMarF670RCAMZVAgLOGZgEF6aAc6cNFSzuMlAW5sTZrn4rMq160SEG1IrA8q 16L3OBrtv5JkR5OcrecB92Du0F3psPdT+KlcV0RXpNRlEEI1c7uF42c8OYDGA2arsbg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590069; 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=hlmdooGeGdqKLPNq1lumye3RsZHcD14xDFFL819Gdic=; b=b6kjL/oDV+hNpbR6jorrkOleQDDq0/zuGyrpG3rNdWmhU90QDjFdZ8ERv6hQvJXTNY4X k39Ck/aVexXbeGS8TFOsqpVI3JyKRIx/SyoBIjzlCK3zjFQBU6/EWXsVRWIGq/mceTnxC 3sXbVVOp3G3eoXj2H4notF9K+wdaRRChGkoEtso5upbYxE/PiMYk7c6dLsJD7qcehUMkp JvKLNisk2eqWZgKI/0SpBSQq93W5P5Z9Dxpx7uVuBtbfGsSojvmODW1ymesY90nBPNz1A BvmT1iy9WNEnO0dWN22t+DTQE4g9wkrSucudCL+1GMiZeS9ub5waItWL6j9cl8bGDvw== 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=2XI8Gj8F; 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 7BCC3606C086; Fri, 13 Nov 2026 17:14:29 +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=2XI8Gj8F Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28ABD1F000C7; Fri, 13 Nov 2026 17:14:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590069; bh=hlmdooGeGdqKLPNq1lumye3RsZHcD14xDFFL819Gdic=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2XI8Gj8F6aACExun6ynV+YcRtQCe+Q9L/enzpbrT7g0P/T7PzlP6cLIgF+9KL+M/n t2+X4NdPhXgo9ukc87OOiSDg6Hpm0dGP6wMsYZlDArvI/i9zcGZVFN1mmXG9US9jXx R1op+lcaU+ds5M86SnCePgmiHXOO6xTcMHQsrFbo= 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 6.18 101/686] wifi: mac80211: queue frames while off-channel Date: Fri, 13 Nov 2026 10:43:54 -0500 Message-ID: <20261113153824.278981741@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@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 6.18-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 63867702ab08a..b012451f45253 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -269,7 +269,6 @@ 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; @@ -277,23 +276,6 @@ 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; @@ -806,6 +788,33 @@ 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]; @@ -1852,6 +1861,7 @@ 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); @@ -4691,10 +4701,6 @@ 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; @@ -4771,11 +4777,6 @@ 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