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=1794282362; b=vlyHs/AKRfdeTUlpYxs4avai7JLzO78iFiiDDWhIFRDGhEHvctaqPifI5Av/U11RoCxw JTgMgMw6n9IjEcq1gf5zL+NTftA/sMStiPd2+820HUk4EOOfDc9LAVA8BJr0YTNtt6dg6 XpwNHjZrVX7hRGb1suDIztBQPxsLo81H2EuG3YrBMvITt1b7Ef9MwUjXYx+00rzBtjOcY FQfE0d4g+eBz57gvqyUifzv0XAgEdMIT9+asVioHiso+ueCykihgIa4AHdIFkacE0tyTj 86iFvZSyBXgj0jLQ565tb61seqrg6Y1EXjyYDGuxev4tB3aNaSYZPD9XZibyd7oSDsg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794282362; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=w5yHBccVuQxqYLVztBxHoYD5jGk6At/Ytv5dFI/mhzM=; b=SRTB9H8xipvVj/Iyt34aBQY8aRbo3SQf7qq6l9s3KMrjjDvTb3moZ77+6D7T6qPTgmrL 8n6Co+bPOQO8+2c9m2aLkRDBEVoH0kiPNf5Mra6FDXWBt+A4YaUF8DiQfozCn2sIaMvYn orstXjv5buFLEOijz4G+yKjk+gMg786hqHLPAEVO/NxA5f4a/A1WHe1Ymjc+Ecsme8NkM 61uzYcAFJG6S/wcw6tFDWTMEd/Tbii57bjefB3eGjJF7rHmW/Zcjso89j/4sFbveU3A1G jV8LzbLabCVkBmmjku73JU9cqdOJNhb37FXYmXrnhPdA2grY5Gp0HN3B728O6FOL2fg== 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=jedlHxwD; 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 771B6606A325 for ; Tue, 10 Nov 2026 03:46:02 +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=jedlHxwD Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80F7A1F008A1; Tue, 10 Nov 2026 03:46:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794282362; bh=w5yHBccVuQxqYLVztBxHoYD5jGk6At/Ytv5dFI/mhzM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jedlHxwD+bDmWzJU55ob1qk2IQyFUpBQ5KgsHJHQXodyHk+m1zT3i8YX9FZcmSuRi ZMcamHOrG7R9szRubz4okHJXheXtflCt0gN/W85KSZc8g5U8gtIslWod0zQ846BDzw aLQYaNqBNqSmpaZTxcbqRI4TgvOC/Xd2zU7c7QlytP6qcSuA6kjamYjlHu3k4q8bpN Cn9i7lLAHnVD6ziTHmOe7O0mS0sHukgICwYzLTtCkJ+xg6DHY6Zhp1sqV3aWqZRFfB sVk+pZPiLNgX0sRd4vYqyTkm1xxlGl/AbRm7Mq8tqwwn3Kt9nb9G5b5r2+YGFtTgTN yIS39m/LGoKhA== From: Sasha Levin To: stable@vger.kernel.org Cc: Stanislaw Gruszka , Johannes Berg , Sasha Levin Subject: [PATCH 6.1.y 2/2] wifi: mac80211: queue frames while off-channel Date: Mon, 9 Nov 2026 22:45:58 -0500 Message-ID: <20261110034553.250150-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261110034553.250150-1-sashal@kernel.org> References: <20261107054118-failed-6.1-13e51269b665@kernel.org> <20261110034553.250150-1-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 36ea274efd051..028e5d25d005f 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -282,7 +282,6 @@ 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; @@ -290,20 +289,6 @@ 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; @@ -829,6 +814,33 @@ 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]; @@ -1887,6 +1899,7 @@ 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); @@ -4552,10 +4565,6 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, skb_get_hash(skb); } - 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; @@ -4617,11 +4626,6 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, info->control.hw_key = &key->conf; ieee80211_tx_8023(sdata, skb, sta, false); - - return; - -out_free: - kfree_skb(skb); } netdev_tx_t ieee80211_subif_start_xmit_8023(struct sk_buff *skb, -- 2.53.0