From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 43716CD98E4 for ; Sat, 20 Jun 2026 08:54:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:Content-Type: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=uZHSWLvj9OPXqYMo+gcDi1m2qcLBOu8zkp0WPfo48s8=; b=Q7Po2uBX+juw3TVsSyepWh8/yT dkRKgwUDP7jWWAJ+7M/IK1hoPhnWjxxBrdG0rQ9iCSlJQ2LkYgaSk7r+fBSnCnX5BodsEOFVLIh+c +d9T9eWug9tdBDOsS3Hl0KaUmyVYQ5c+ffRv8gYTSP8e3EjmKA4HBmObOKClUaKjbUOcRkYYMjhmo 7QlBN+cE14qyci+U42KEOviHuwygz5v2Et7J+/HaJFMM1amSQAo2UzGtYMyR7NHCJv4yLoblMcq3v OuHZ1ULgQlkeuM9+axHgc9WXjw0v36NYKMBwWd1hkPpWVwbJYjV1nXYjO1DIf6eSw08GjE6IXU+Mv OdPSWOpQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1waqx2-00000003F5d-1t9f; Sat, 20 Jun 2026 08:21:16 +0000 Received: from mail-pj1-x102c.google.com ([2607:f8b0:4864:20::102c]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1waqwz-00000003F4v-2NH6 for linux-arm-kernel@lists.infradead.org; Sat, 20 Jun 2026 08:21:15 +0000 Received: by mail-pj1-x102c.google.com with SMTP id 98e67ed59e1d1-36b8d414666so1519969a91.3 for ; Sat, 20 Jun 2026 01:21:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781943672; x=1782548472; darn=lists.infradead.org; h=mime-version:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to; bh=uZHSWLvj9OPXqYMo+gcDi1m2qcLBOu8zkp0WPfo48s8=; b=CcU6pgmds+apkAPRorY3CsdIEFjMLAnUKYog7wI9rSCobHLICRJGoNAETQszUtAovJ py1+jc3w8JcLeGk//EPo/7U0/CyZJq0V2D5fQdSwhDsPX1OGHxA9Y+y0juhBNdhjipj1 bfdu9v2lnU+b/rOW0NY5NxdPdv4HpPPWj5ZtgopEFN1Sb7QVWnuIuJhQq58BOGg+ow0J Xa9I7r5JRZensClrsZPp51U88ldsGLDIk/Bd3hIQ1IWgn+3+dhjdESX9SKeJYqCzJy6V FBXLOgB3UWGgyu59IgAxO+JV8wMMKF9qnkx5dPZzhARRLuNPpuooYJjFLW/nIvT1OFYJ zadg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781943673; x=1782548473; h=mime-version:message-id:date:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=uZHSWLvj9OPXqYMo+gcDi1m2qcLBOu8zkp0WPfo48s8=; b=LVgZmDovk7GdQ3hzd5hAKRKKaGt0Sl2ODNaAS4c2FLqmOxtw3HKxtGVZcESOcMqoeo JvJcfSHYjEItPsEwvUdMWrWYPGWpUcoXx1QP3aet2wenVAJfWywN88fKab4q70BG44it C//aWrbsAD/9IbIjKmaIoieR7xrVE/yBXDpriIDJ+23Kh9Qjk3HCE9ncn3p+T7FXYnVE H5wohpvsl2v5eoPfu6Un/bGPuqnidoON0jzm+0pEqU2nhUZYNlsqsF1C1kzUBtklq49H zVPztLEmv6wJT0h6qtnXP7JzttshFvEXen71iYD7oGTR41mgzMABOiOKNIuJFUyebEI/ Zw5w== X-Forwarded-Encrypted: i=1; AFNElJ9VofySrvPTncwGun2GVr3imOe1fsPdaygyaGrv96Bl+jaFDEpNnWH+314h8EDmMqmlNvNvNBIVvQcsUIfV7DO5@lists.infradead.org X-Gm-Message-State: AOJu0YxJPH2O/hNbfzF1C/MtWyVupPNAn//Rv7CoL0otizY9Fue3/BLy Raur7FymK0BBvg0v7F4vxsOW0q1QRhzm2Lq5+sxeGi+EywoaCOJBZ0hj X-Gm-Gg: AfdE7cmx7wQKtnzoYXBU3FVYHSOgYNzMtLNcEDlvoEWLBlVf6NV4lmJZD4CW7sP8GxI XXHZNGbTABvQa16WeBt7cawhVDYgtr8qk7o2hvg21gwkTTjsmS2GbgkYqz8IUS6I1G7iA8iqJwv FJ3tZhx8nFQME8DQzPWUW4pm+Zc+Lnq/FQUJwwegDJtBpJd06UnhJiz6xxIhrBjcgqnYSS2BOLJ cXBpJd7SYrnTUqQT18CMGhK70aNyyUQUMSJe3nRfSFjP3T3bZUGROi6tlAsIEOhYvEuvdzysjob rD8r0PwZLN8qNmBwvhci6ldivXEX2kYyJDjob/LhgMeCkA4jIRM0mLBOF5CKkEcqJHkQIZss0DG gasVDskwIAdvPYb41bnivvDve7rCA4/9QjRNnPIpZczev+hP4UroGxwFOQVocrpnpn1yqEYFegR 2dQoWPtQ== X-Received: by 2002:a17:90b:5884:b0:37c:806b:3ca7 with SMTP id 98e67ed59e1d1-37d4d71d969mr2357014a91.3.1781943672584; Sat, 20 Jun 2026 01:21:12 -0700 (PDT) Received: from [127.0.1.1] ([47.253.114.73]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-c8bbffc2329sm1786971a12.0.2026.06.20.01.21.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 20 Jun 2026 01:21:11 -0700 (PDT) From: Wayen Yan To: netdev@vger.kernel.org Cc: lorenzo@kernel.org, horms@kernel.org, pabeni@redhat.com, kuba@kernel.org, edumazet@google.com, andrew+netdev@lunn.ch, angelogioacchino.delregno@collabora.com, matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Joe Damato Subject: [PATCH net v5] net: airoha: Fix skb->priority underflow in airoha_dev_select_queue() Date: Sat, 20 Jun 2026 16:17:44 +0800 Message-ID: <178194366700.2485734.5368768965976693502@gmail.com> Content-Type: text/plain; charset=utf-8 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260620_012113_639395_48E58099 X-CRM114-Status: GOOD ( 10.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In airoha_dev_select_queue(), the expression: queue = (skb->priority - 1) % AIROHA_NUM_QOS_QUEUES; implicitly converts to unsigned arithmetic: when skb->priority is 0 (the default for unclassified traffic), (0u - 1u) wraps to UINT_MAX, and UINT_MAX % 8 = 7, routing default best-effort packets to the highest-priority QoS queue. This causes QoS inversion where the majority of traffic on a PON gateway starves actual high-priority flows (VoIP, gaming, etc.). The "- 1" offset was a leftover from the ETS offload implementation that has since been removed. The correct mapping is a direct modulo: queue = skb->priority % AIROHA_NUM_QOS_QUEUES; This maps priority 0 → queue 0 (lowest), priority 7 → queue 7 (highest), with higher priorities wrapping around. This is the standard Linux sk_prio → HW queue mapping used by other drivers. Fixes: 2b288b81560b ("net: airoha: Introduce ndo_select_queue callback") Link: https://lore.kernel.org/netdev/178185573207.2378135.3729126358670287878@gmail.com/ Acked-by: Lorenzo Bianconi Reviewed-by: Joe Damato --- Changes in v5: - Rebase on net/main (previous version was incorrectly based on net-next/origin/master, causing Patchwork CI apply failure). Signed-off-by: Wayen Yan --- drivers/net/ethernet/airoha/airoha_eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index 64dde6464f3f..3370c3df7c10 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -2110,7 +2110,7 @@ static u16 airoha_dev_select_queue(struct net_device *netdev, */ channel = netdev_uses_dsa(netdev) ? skb_get_queue_mapping(skb) : port->id; channel = channel % AIROHA_NUM_QOS_CHANNELS; - queue = (skb->priority - 1) % AIROHA_NUM_QOS_QUEUES; /* QoS queue */ + queue = skb->priority % AIROHA_NUM_QOS_QUEUES; queue = channel * AIROHA_NUM_QOS_QUEUES + queue; return queue < netdev->num_tx_queues ? queue : 0; -- 2.51.0