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 CAD38CAC5AE for ; Wed, 24 Sep 2025 23:05:46 +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:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lOYXUZPcEtyXx8TJkCgGe4mqf5vnthhRGIqJQbgt5/U=; b=QKwEOsXcBBBJDMYylkST+fZCHm X22HCZ2/tNl+N02x7lNNL9P2gZ+s/Wxnh+dT/7AVQw1ofHGAZ4bHw6dHIKJZufQ4XFBa8ieXdnjqB hvB3QL3Xehxq6ij4MggnP97yS9YDlm6mQlPyyiXi/EXWOhMWrL+uDYwX2kUqpP2c9oodQQLyLpK8u oluUYPTO83PURm0avvdmaDV1XcIfHy9QtmWFce4Wp5mhaobum+T5ZMVWr5eKVC1J7nG0SwT/U/1tQ eFAE9YE9wv58HGe0DKuCyD8twNkPD9AAx0s+wrsnXIdZKB6U/TH81YEVS3HHoDliRYZnnXflZuhl+ Y2Xo6lJw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v1YYO-00000004Wvg-39gz; Wed, 24 Sep 2025 23:05:40 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v1YYM-00000004WvC-0sF5 for linux-arm-kernel@lists.infradead.org; Wed, 24 Sep 2025 23:05:39 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 91D71415F2; Wed, 24 Sep 2025 23:05:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABB16C4CEE7; Wed, 24 Sep 2025 23:05:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758755137; bh=5nkOcXtCrUSyUylrHVFJ3GThi+rvDI6+s49nr6gVhIE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=o2B+AppW01bYd+MqBDecD+SP/V9GbfDTxn/PBf73IXN0zz71y/75bOrFOH1ffL15l USGG9YEhz/ZHlUOgLnforvbQS70LJIVGswy1eM+35tuLEoraYhcsC4TOMRB/nDPuP9 UADMv215SbIq3RyGg+xQmp5dQE3fV9nuKNwp0YJI2/OLnxu07gQV3lZez3r72J2WPx HSVgGio6T3k726XlmEkC3RNro04vRJDTrStw/cz/LJD4R/4yLir25W9T8CwRkGhQtw zFjHFI+2VjPlHvpJveCKeZrMfZC6ylNEHRf2mC9dv1I/l9MGMjgTl68qnLo78IAmRP QtvXZM8V6kR2g== Date: Wed, 24 Sep 2025 16:05:35 -0700 From: Jakub Kicinski To: "G Thomas, Rohan" Cc: Rohan G Thomas via B4 Relay , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Maxime Coquelin , Alexandre Torgue , Jose Abreu , Rohan G Thomas , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Matthew Gerlach , "Ng, Boon Khai" Subject: Re: [PATCH net v2 2/2] net: stmmac: Consider Tx VLAN offload tag length for maxSDU Message-ID: <20250924160535.12c14ae9@kernel.org> In-Reply-To: References: <20250915-qbv-fixes-v2-0-ec90673bb7d4@altera.com> <20250915-qbv-fixes-v2-2-ec90673bb7d4@altera.com> <20250917154920.7925a20d@kernel.org> <20250917155412.7b2af4f1@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250924_160538_277854_05557B28 X-CRM114-Status: GOOD ( 16.72 ) 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 On Wed, 24 Sep 2025 10:24:44 +0530 G Thomas, Rohan wrote: > >> Is the device adding the same VLAN tag twice if the proto is 8021AD? > >> It looks like it from the code, but how every strange.. > >> > >> In any case, it doesn't look like the driver is doing anything with > >> the NETIF_F_HW_VLAN_* flags right? stmmac_vlan_insert() works purely > >> off of vlan proto. So I think we should do the same thing here? > > > > I suppose the double tagging depends on the exact SKU but first check > > looks unnecessary. Maybe stmmac_vlan_insert() should return the number > > of vlans it decided to insert? > > > > I overlooked the behavior of stmmac_vlan_insert(). It seems the hardware > supports inserting only one VLAN tag at a time, with the default setting > being SVLAN for 802.1AD and CVLAN for 802.1Q. I'll update the patch to > simply add VLAN_HLEN when stmmac_vlan_insert() returns true. Please let > me know if you have any further concerns. SG, no further concerns. Please make sure to CC "Ng, Boon Khai" who wrote the VLAN support (IIRC).