From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AA5CF17BA2; Tue, 3 Feb 2026 01:44:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770083046; cv=none; b=Sw4YJvjcmMzm/LBGmIcalBcz7o8GMZFvk2WTNzqnbnGp7AG2+6GCk+ZI3vT0W6HAvTB3Oe/WnlubPKO40gJ1mLMm9rQuLc+n1tQf6l5K6WUmZVZSMCqG+aEb/cCQk4T7UnbCdUKr00w1IRAw0gIv9s6DOLy8ubEGQfM+CQx4bAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770083046; c=relaxed/simple; bh=Qjhb1uOmk8zQdQk9UtlBXnrX95dGDnTVIYt+n3+66Nc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ESvui1hgQy5p7uwefFwuHUxnxdNF8lVhtm523C/tivmiHXzpm4Nlhr9AqIdi7IdPyWHxSiVqwPQdJDtnVwywSVEBWUCSIrfUzVvWChDNdav1A8mXa2PGhQ5y3/2v5nuwViL+AUe/s9BBbjA9A+FvorEYgony408W7596bh6ZdkY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eksgF6Ke; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eksgF6Ke" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B55EC116C6; Tue, 3 Feb 2026 01:44:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770083046; bh=Qjhb1uOmk8zQdQk9UtlBXnrX95dGDnTVIYt+n3+66Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eksgF6KeSDnB22KMtBo4iJ1Lw6l5LB0Idkr5dSU5b4hvPfdIKuaJM59ukY1kKP0iY tbZ0t6e+vv0TpkmZjnQErC5DJil6gKCSVdLJheYCRy8eX8JdQxYkwlIok9TBoz4RMc qPzAk69z8z4HMVrVlazeKNepwvKCB9T54+IeUnA2uX8nwZJCpG9lKosv+Kg/Ly+eB1 +lrjojCZ1j3P6QWeKWumZk3muazz2C4xRQsF57BiL4uNX99XXD5+X1yPYaMpuoNJIi hUxcZDpZQINEQ1McfRcwYPmxnUBu0Su2WzWixKw9dI5lUuRRGfzNvNeBaLJShsKOyn MV83gK3DiXOJg== From: Jakub Kicinski To: lukasz.majewski@mailbox.org Cc: Jakub Kicinski , andrew@lunn.ch, shawnguo@kernel.org, krzk+dt@kernel.org, linux-kernel@vger.kernel.org, edumazet@google.com, netdev@vger.kernel.org, pabeni@redhat.com, andrew+netdev@lunn.ch, davem@davemloft.net, conor+dt@kernel.org, horms@kernel.org, richardcochran@gmail.com, robh@kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, wahrenst@gmx.net, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com Subject: Re: [net-next,v22,4/7] net: mtip: Add net_device_ops functions to the L2 switch driver Date: Mon, 2 Feb 2026 17:42:48 -0800 Message-ID: <20260203014247.824561-2-kuba@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260131233459.1625279-5-lukasz.majewski@mailbox.org> References: <20260131233459.1625279-5-lukasz.majewski@mailbox.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This is an AI-generated review of your patch. The human sending this email has considered the AI review valid, or at least plausible. For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html --- net: mtip: Add net_device_ops functions to the L2 switch driver This patch adds net_device_ops callbacks for the MTIP L2 switch driver, including transmit, multicast configuration, MAC address handling, and timeout recovery functions. > diff --git a/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c b/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c > --- a/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c > +++ b/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c [ ... ] > +static netdev_tx_t mtip_start_xmit_port(struct sk_buff *skb, > + struct net_device *dev, int port) > +{ > + struct mtip_ndev_priv *priv = netdev_priv(dev); > + struct switch_enet_private *fep = priv->fep; > + unsigned short status; > + unsigned int index; > + struct cbd_t *bdp; > + void *bufaddr; > + > + spin_lock_bh(&fep->hw_lock); [ ... ] > + /* Save skb pointer. */ > + fep->tx_skbuff[index] = skb; mtip_start_xmit_port() stores sk_buffs in fep->tx_skbuff[index] and creates DMA mappings, but mtip_switch_tx() which should complete TX operations is empty: static void mtip_switch_tx(struct switch_enet_private *fep) { } The NAPI poll handler mtip_rx_napi() calls mtip_switch_tx() to reclaim transmitted buffers. Since it does nothing, won't every transmitted packet leak the skb and DMA mapping? Also, dirty_tx is never advanced, so the TX ring will fill (cur_tx == dirty_tx) and stop accepting packets. jakub: maybe add a TODO comment transiently here, since later patch implements the cleanup? > +static void mtip_timeout(struct net_device *dev, unsigned int txqueue) > +{ > + struct mtip_ndev_priv *priv = netdev_priv(dev); > + > + dev->stats.tx_errors++; Jakub Kicinski noted in v16 review that tx_errors are already counted by the network stack, and the statistic is exposed per-queue in sysfs. Does incrementing tx_errors here double-count timeout events? https://lore.kernel.org/all/20250725151618.0bc84bdb@kernel.org/ > + DO_ONCE(mtip_print_hw_state, dev); > + > + schedule_work(&priv->tx_timeout_work); > +}