From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 D340732ABFF; Fri, 17 Oct 2025 12:44:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760705087; cv=none; b=Il2+NdpVXKUce4hPCLy3okGZmZWHbba4FyrJ5Pe0DNOgLuzxcwdM81w2J53eekgf4ELuE5v2fT77/gmBzcNCEXdpLf3uNbgcy7UX05Qx9drBrl6umkIn6e9nyWGLxYdE0RO/k+XU/zt1gZgiZgR4KhmiMdAnnUkOttHJFZ2BsuE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760705087; c=relaxed/simple; bh=0QgbZU9irSNV/N076JQZk6AJrYALmk3Md2UhCibShyQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P4tZmfq+9WV8YH0qwKEHcqthW1sSFbafY0hVBTXzZCyYccAO2U/fzXguRV28wUjVaio29hO49u9HP4qwLkb28YDRNzOPLUCDeRcn3zBNyYpX/dgTE9H6Bwiy+FYyqp0XOKxjL3gNPUWh2TFdhVsdR/wwRI0NWFgZD+6EiXznhUs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=eaCyIulF; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="eaCyIulF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=iMaunYaTiHBvajS7Akr5txw8OUSAxQkTAc82E7olhqA=; b=eaCyIulFQ6xXo3jsBkivsFl4D/ eX2T8893dgSWPXh0cB9jACnVhOKEftIlnkvKdgnTBqdyc5p81MVz6fbyELEM3BxWyq6MkccMQBaRe u58byjoq7OPLCF3H5LTWYkPJx7qu0a/yUatYpBiWM7NoDtVEbCzIHayP22SbhtnHvdkeeG1g8cro3 eYu93lp8g+6CLI6mvoLnmagZtbsA2h+fpTOa//ygkATewPSSWzSHBwzR0ObROGZPTRZxXX1WaqMQf zfbONHfMmySV7TT5o21EKlk6UP0k9p2He0SK4PXGt7oPhbylRTUmdNUQLofl/7pJ1c7MRzntD6eHk SOcZZeEg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:34722) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1v9jox-000000007tY-2bB3; Fri, 17 Oct 2025 13:44:35 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1v9jov-000000004Jy-0MNd; Fri, 17 Oct 2025 13:44:33 +0100 Date: Fri, 17 Oct 2025 13:44:32 +0100 From: "Russell King (Oracle)" To: rohan.g.thomas@altera.com Cc: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , Alexandre Torgue , Jose Abreu , Rohan G Thomas , Boon Khai Ng , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Matthew Gerlach Subject: Re: [PATCH net v3 2/3] net: stmmac: Consider Tx VLAN offload tag length for maxSDU Message-ID: References: <20251017-qbv-fixes-v3-0-d3a42e32646a@altera.com> <20251017-qbv-fixes-v3-2-d3a42e32646a@altera.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251017-qbv-fixes-v3-2-d3a42e32646a@altera.com> Sender: Russell King (Oracle) On Fri, Oct 17, 2025 at 02:11:20PM +0800, Rohan G Thomas via B4 Relay wrote: > From: Rohan G Thomas > > On hardware with Tx VLAN offload enabled, add the VLAN tag length to > the skb length before checking the Qbv maxSDU if Tx VLAN offload is > requested for the packet. Add 4 bytes for 802.1Q tag. This needs to say _why_. Please describe the problem that the current code suffers from. (e.g. the packet becomes too long for the queue to handle, which causes it to be dropped - which is my guess.) We shouldn't be guessing the reasons behind changes. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!