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 598C8C5DF9B for ; Mon, 24 Aug 2026 12:34:02 +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-Type:MIME-Version: Message-ID:Date:References:In-Reply-To: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:List-Owner; bh=LYsstLUHA4+O8kBjsO8+8kq4A2q37DKWSh7yXTB84NU=; b=YRmBFvnWoUmbAnqPJWGbD6QrVj fy5WjD+fHaX89pQBOanOI1R2DGLQr9xYaB9mfgMoViDCe0/uQLwk1IE3NEP7ErysLKHNeM75Dm9S/ UXDQokWJfGC8V/k2iDajatRocCplo8sNw2XMKxEHH5NWVgfzC2l1YaFWQOi3VVOZyb8RLuaUXljku Tyu35941pL8GK2tZEwdCNyGu4xix9mnvZxTGTe9msXp0Z9UQQ+D3pmdtuJrjG5YCgZYgfpRjvXj0O EsLrklofdvidU3VH99pCKHqfnWZXcnFjiGgNJSTyEwaQnjgoigdhcZC63ejTRBHVZxRObyzH3wfFR CC2LgojA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wyTs5-0000000Gc6P-0JjP; Mon, 24 Aug 2026 12:33:49 +0000 Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wyTs1-0000000Gc5t-3xEe for linux-arm-kernel@lists.infradead.org; Mon, 24 Aug 2026 12:33:47 +0000 Received: by mail-ed1-x535.google.com with SMTP id 4fb4d7f45d1cf-69c600f76ccso5703947a12.0 for ; Mon, 24 Aug 2026 05:33:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffroot-co-za.20251104.gappssmtp.com; s=20251104; t=1787574823; x=1788179623; darn=lists.infradead.org; h=content-type:mime-version:message-id:date:user-agent:references :in-reply-to:subject:cc:to:from:from:to:cc:subject:date:message-id :reply-to:content-type; bh=LYsstLUHA4+O8kBjsO8+8kq4A2q37DKWSh7yXTB84NU=; b=qHKj2b947M0g9b/BRq7C/YPlrNlJy3gvK2xW5I8YP/7xhCXe9YZhG5BbvOue7ddquD Xs611c6tGT+16ghVQZUHVHYME/IVbn3AjYN98H3rzzV9OmUQfPa9pfQNsvVhLR3uLnIB bKeWq4PD2lm0TO1fwhxAhNzpk/lQmmwIK7cMJNx5Qn//+U3Y2ByZL/xwzuliiqMmU2A+ l34rCCifmn+5ui4KzC/UfI5Oh9k/ECaHq19TQwpRZ7aKzEr7zzCSs4qI+NJNdyDoVItH ig1RbCaliDEn5/Qequysttu7C6Kr7+7PbzIpii0ZaCICln3pboPtwDioMLMuuv8g6Y1h 9m+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787574823; x=1788179623; h=content-type:mime-version:message-id:date:user-agent:references :in-reply-to:subject:cc:to:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to:content-type; bh=LYsstLUHA4+O8kBjsO8+8kq4A2q37DKWSh7yXTB84NU=; b=eq2Y57v8DK1GvoAwZw+90p3fI946twPAZdoKqz0AWj/hKchgkpQyDBhzUAP7m0o/d/ mPW/IzL9FI91Y6122gQHeOd/vnp0DHy4/FTxsrYdAt+IUT9Amy2GKdF4mJwI7ft06Fd9 jWKOtFuQYXh55y1V2GRwOVaqDuRn8V7Fzi8f0hhwPj4YWxfFRmfIK3pfHSG6YBvK5HfF W6IQ+GqT2c/GwP/eQoDCkUf+Pig9U6qymjNZOs7JhjgcuW6HDQvbe7p/zRWV8WY0gUHY /a1CruAOW3QJ4GKCUFp9qszRoG9aIlyQ2VJfAIpRl6mhNNIiKO5I/PWe349Yuu8jV0t2 iezg== X-Forwarded-Encrypted: i=1; AHgh+RoiSgzEuVSAALl2+7ou2uVAg1cd+nhPwhPKGg+oglPLxBYhmgTNVRMFcL0a4rknw66Cd5MssS4vKdoQBJejts5e@lists.infradead.org X-Gm-Message-State: AFuF++nhEGNlrZv6ysJipn3TY4N5d1lybNvwXB31bfKbudF9Cu08ZR7u QOWEz4LACCMB/is6NQEehsZPwD4JqnOQdQDUO54tDkYY6r/fxfZS52m2wiilgq4BZlVMn4NKQaK hjAv8eNA= X-Gm-Gg: AR+sD10+wSw1dPcBMtBZg8qKUr9ybmCIdVcb7FDJtlvN+z9rijnXT82M18Jx2doQS5K eKqnPwB03eVQDyZJv4tIKTcVN/APag5hdbi0K8t70ZCmkHnu4D3sP8nDM5IVFvbl190I5jaDMZe HxFRU3W1/oc1SPIUomd8kIRKU8Ki3FWrYUqpb3zJgOC+2Ia7qPig+rzfTz9JpcPibQOKvY5XqkK Y3kN8ixdQcmOpRaDp3eALRx5o2LQCe+7of6SiTBI+4gZZrI/ykhhQfpNH2p4KJGAGqe3OD2ppFM nbiX6+54HHV444/MfJXlWkADtDkFMklJ7B2gOPjZoFrClBEk8J3xlhGRxn/I3hIxZX+OM1M8aq5 8m+IKJLJnHFn6c9GMfaTYtslEIYry0ewrXSB3jPQhP3R5tHQr1ZCHdYUyMOo+2r9900qLHCksYH s52fTFinWDeJmSeCKalMwKBRkMibtWLxF+WV5FqSdXo2Uze9nAIG/M9r3kUG7kzO4VChoN3OAjX /fbZtBQUYLOz43m X-Received: by 2002:a05:6402:24c8:b0:6a1:4458:7f2d with SMTP id 4fb4d7f45d1cf-6a42f172088mr22058897a12.5.1787574822559; Mon, 24 Aug 2026 05:33:42 -0700 (PDT) Received: from dev-ag ([102.33.165.38]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-6a59e1d741asm8342424a12.27.2026.08.24.05.33.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Aug 2026 05:33:41 -0700 (PDT) From: Andrew Gaylard To: Jakub Kicinski Cc: netdev@vger.kernel.org, wellslutw@gmail.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] net: sunplus: fix tx_poll spin_lock missing irqsave in NAPI context In-Reply-To: <20260822135103.6711ba25@kernel.org> (Jakub Kicinski's message of "Sat, 22 Aug 2026 13:51:03 -0700") References: <20260820130159.1584806-1-ag@ffroot.co.za> <20260822135103.6711ba25@kernel.org> User-Agent: mu4e 1.12.14; emacs 30.2 Date: Mon, 24 Aug 2026 14:33:36 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260824_053346_121340_8B5E3591 X-CRM114-Status: GOOD ( 13.43 ) 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 Jakub Kicinski writes: > On Thu, 20 Aug 2026 15:01:59 +0200 Andrew Gaylard wrote: >> spl2sw_tx_poll() runs in NAPI (softirq) context and acquires >> comm->tx_lock with plain spin_lock(). The hardirq handler >> spl2sw_ethernet_interrupt() acquires the same lock, so a hardirq on >> the same CPU while the NAPI poll holds the lock would deadlock with >> IRQs disabled. Use spin_lock_irqsave/spin_unlock_irqrestore. > > Please explain how the issue was found and how the fix was tested. > I mean - this is an ancient driver, if you don't have a way to test the > fix you should not be sending the patch. I'm testing on a Tibbo LTTP3G2 board: https://tibbo.com/store/tps/ltpp3g2.html This work is part of getting it to boot, getting it stable, adding a couple of missing drivers, and sending the changes upstream. I found the issue using lockdep. At least, I though I did, but I've not been able to reproduce it, so I must have been mistaken. Apologies. Please drop this patch. -- Andrew