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 B8B32C83F1B for ; Wed, 16 Jul 2025 21:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc: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: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=ZvjiIuDfrlWWbykzDv6yMKlbKFJ9c3SfR0on8ygzWv8=; b=hHzeJ7asPmdIfi hvvb35juCTGIsPOlgcFIv51sgEOg8xtKUGy4ZSSKRep6kMZWaEsg6at5kQtvByi/tcEyv+xr4mAkr nonHVk3n4ewqFEcC6ZY7aRvLTc2GeZQXuAViQXb0bJlDlEkqnbgGJvotjlUWNDrvNm7FK2PopETOB x2FB7wBj8hK9lOpj0LAeDXVtWU+iogGbF6A8ZgzEj4hCjxpEqQ3n1YbtOeaxgg3fe9DHy/d/uTecx giMXUg5iIA6XrM/IOMnI7WMZS54R34/kLvKNlQ9a9c8RqL9bgFeUQUwqFevevGf6nW7Z4TxVwTkKJ CXqmM9VC8ala0R71xuzg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uc9bm-00000008hA8-2aTd; Wed, 16 Jul 2025 21:24:10 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uc9Nb-00000008fqz-31eh for linux-arm-kernel@lists.infradead.org; Wed, 16 Jul 2025 21:09:31 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 36E76601BB; Wed, 16 Jul 2025 21:09:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1FEAC4CEE7; Wed, 16 Jul 2025 21:09:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752700168; bh=ZvjiIuDfrlWWbykzDv6yMKlbKFJ9c3SfR0on8ygzWv8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=MihocQ5CfRgKpACI/aeFhkJ5efmhxN3ecKFo8AYnY89VPMXR1C4T9t3Q5aqmsISYQ qCkS257leQLzb3LjhZJLla7Ra3zItwwNU0vjngd7HF8DOwzYXcApTXAtRKMdASzWXk bsIuuYDUqO8H9+hXjPIpDIyxKpdq9ojwWIjBZpnPONeJ+NUMqJfY9apufkcTpVxGf+ mqxztjqJ45Cuf0YQFLrSYrn+NgT04N5m5cXOPE0zL4wk8Md5xd1+z++31VnqlA3wDv MPZi8dXrwsIGfwlsTYa1mm6JKvAWH2KnMbiq1NDRbD5vdqWTAuBn4wx7y3ZTYAYN7r p1LStuyyw3sgQ== Date: Wed, 16 Jul 2025 14:09:26 -0700 From: Jakub Kicinski To: Parvathi Pudi Subject: Re: [PATCH net-next v10 04/11] net: ti: prueth: Adds link detection, RX and TX support. Message-ID: <20250716140926.3aa10894@kernel.org> In-Reply-To: <1616453705.30524.1752671471644.JavaMail.zimbra@couthit.local> References: <20250702140633.1612269-1-parvathi@couthit.com> <20250702151756.1656470-5-parvathi@couthit.com> <20250708180107.7886ea41@kernel.org> <723330733.1712525.1752237188810.JavaMail.zimbra@couthit.local> <1616453705.30524.1752671471644.JavaMail.zimbra@couthit.local> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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: , Cc: Vignesh Raghavendra , praneeth , edumazet , glaroque , pmohan , diogo ivo , robh , javier carrasco cruz , saikrishnag , m-karicheri2 , jacob e keller , pabeni , richardcochran , devicetree , conor+dt , mohan , s hauer , Prajith Jayarajan , rogerq , basharath , ssantosh , Vadim Fedorenko , linux-arm-kernel , rogerq , srk , pratheesh , m-malladi , netdev , linux-kernel , danishanwar , afd , andrew+netdev , horms , krishna , krzk+dt , davem Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 16 Jul 2025 18:41:11 +0530 (IST) Parvathi Pudi wrote: > >> Something needs to stop the queue, right? Otherwise the stack will > >> send the frame right back to the driver. > >=20 > > Yes, we will notify upper layer with =E2=80=9Cnetif_tx_stop_queue()=E2= =80=9D when returning > > =E2=80=9CNETDEV_TX_BUSY=E2=80=9D to not push again immediately. >=20 > We reviewed the flow and found that the reason for NETDEV_TX_BUSY being > notified to the upper layers is due lack of support for reliably detecting > the TX completion event. >=20 > In case of ICSSM PRU Ethernet, we do not have support for TX complete > notification back to the driver from firmware and its like store and > forget approach. So it will be tricky to enable back/resume the queue > if we stop it when we see busy status. IIUC this is all implemented in SW / FW. You either need to add=20 the notification or use a timer to unblock the queue.