From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32472257854; Thu, 28 May 2026 20:18:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999501; cv=none; b=nz6n7qlIrzhVklvw8V1cz7cM0fX3xnPCUgkbdieahPQlr8alFhughK1a2ONKdhRUn0ALXlGFzT9GBlLEs0QSoOF04JJnuFpNnXL7TDudVfAIMpZRbOLKZn6Hle2OKR+zRURTG5DhkUsjvk3GH0O+CbuStLQEd/OXV+M8udDfVI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999501; c=relaxed/simple; bh=yTUAlCqrZqiUXDPzHTsHpt4J9QWFA3/FFTq9qCCQg4M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jlFUMxeZksuBHd23FdVSj1NGi+YgLiCDqwYHWDfTMFsgqwbkWnQC2tYbAgkebXsAJFlsNz/mQUSWBBfqPEEtLNof8NVWimiLjIua3luYnGKnaHSXIhG/hkTtCTgDVTuCfUVHa1hDRapiK+KBWtQLkHGp0qcizwV55ryEv/pGnkw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rHX9Ia+R; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rHX9Ia+R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 908F71F00A3A; Thu, 28 May 2026 20:18:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779999500; bh=tVqFxA22r6BDj4EwjMEy4/nxDiNDW7NpecBEMkkKrrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rHX9Ia+RAuSXy6S9/wolQ4AN3qa/06gqzGs6MCKMlQ+Ll1FZrFAKko3T0WoDFE824 jN16IcqagN00P3E7cnkF+00jMJgUftviFLqtsEFsQsiIfTNQfdHo/5RnQItxD6o/SY a6TBpDXpVOfgKPpeEoRPpfBocWDvIv8sNZCNQLng= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sheroz Juraev , Miri Korenblit Subject: [PATCH 6.18 090/377] wifi: iwlwifi: mld: stop TX during firmware restart Date: Thu, 28 May 2026 21:45:28 +0200 Message-ID: <20260528194640.971451761@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194638.371537336@linuxfoundation.org> References: <20260528194638.371537336@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sheroz Juraev commit 2becb38a3e217ef2b2f42fddd7db7a25905ec291 upstream. When iwlwifi firmware crashes (e.g., NMI_INTERRUPT_UNKNOWN on Intel BE201/Wi-Fi 7), iwl_mld_nic_error() sets mld->fw_status.in_hw_restart to true. However, iwl_mld_tx_from_txq() does not check this flag before dequeuing frames from mac80211 and pushing them to the transport layer. Since the firmware is dead, iwl_trans_tx() returns -EIO for each frame, which then gets freed immediately. Under high-throughput conditions (e.g., Tailscale UDP traffic or active SSH sessions), this creates a tight dequeue-send-fail-free loop that wastes CPU cycles and generates rapid skb allocation churn, leading to memory pressure from slab fragmentation. The RX path already has this guard (iwl_mld_rx_mpdu checks in_hw_restart at rx.c:1906), and so does the TXQ allocation worker (iwl_mld_add_txqs_wk at tx.c:156). Add the same guard to iwl_mld_tx_from_txq() to stop all TX during firmware restart. Frames left in mac80211's TXQs are naturally drained after restart completes, when queue reallocation triggers iwl_mld_tx_from_txq() via iwl_mld_add_txq_list(), or when new upper-layer traffic invokes wake_tx_queue. Tested on ASUS Zenbook 14 UX3405CA with Intel BE201 (Wi-Fi 7) on kernel 6.19.5 where the firmware crashes approximately every 10-15 minutes under Tailscale traffic. Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") Cc: stable@vger.kernel.org Signed-off-by: Sheroz Juraev Link: https://patch.msgid.link/20260315081221.2678478-1-goodmartiandev@gmail.com Signed-off-by: Miri Korenblit Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/intel/iwlwifi/mld/tx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/net/wireless/intel/iwlwifi/mld/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/tx.c @@ -965,6 +965,16 @@ void iwl_mld_tx_from_txq(struct iwl_mld u8 zero_addr[ETH_ALEN] = {}; /* + * Don't transmit during firmware restart. The firmware is dead, + * so iwl_trans_tx() would return -EIO for each frame. Avoid the + * overhead of dequeuing from mac80211 only to immediately free + * the skbs, and the potential memory pressure from rapid skb + * allocation churn during high-throughput restart scenarios. + */ + if (unlikely(mld->fw_status.in_hw_restart)) + return; + + /* * No need for threads to be pending here, they can leave the first * taker all the work. *