From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=194.13.80.246 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793388812; b=nhPe8+QLhyWk7CeWuoNkD7iqLG+vao4UgdzE9UgY2ZwDU6Iv4xvipR/YkhSohV3Scs1J T+aco+ucT2UisW7c4+0e2YUHArIgMVHd2VDUzH+ONZ5F+b9SsQKdXRounA2BanZc1adPZ Dw0oLQn5rCIsla+1flUwID+vTbqL52QeT68G1keNacsNe2Sj2eB6BHaxxtM7oxFxl3Pcr 8wtoJVJE5FLQC9P5zgsQu7X4qdNgVGrx2GpKkL89ctpfQjkhQtIAwPPOo4wR6vTcA7/eM bFjnzOGDBmxgNKGtjE0BR5AbteIV7O4PojXaAI/gAtIZmg7ElawWFONqVDrYeYiw2pw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793388812; h=DMARC-Filter:Received:DKIM-Signature:Message-ID:Subject:From:To:Cc: Date:In-Reply-To:References:Content-Type:Content-Transfer-Encoding: User-Agent:MIME-Version:X-Last-TLS-Session-Version; bh=QtGA4oygWFl5CX8vg4imBuTm2I065I8hD6TIKVaKg5Q=; b=UOrDTrosYaaGYxVWDkuNzuxP1syHdvMqbe9q7fQnqKJgXma572G/mEnvQQN9ksk0NGAu D3YwFQkY+5aZdTqWMjik2N3FerdFisFqNJ6GD0pKuyA6iHyJWxpdKnyPmelnbYdH2fmw8 lXJwvYPmsk1HDCouFqr1/TxPJ3wiY25kjafHveXe1C/qh6Hi+DWq1P1ScCNORqjLU17ba 3o33rohoFYBwCfm2RZpzstl7fxdH4kBsCddux8LEh6bt8rLuXy0W9xIyAz7PAL6S0dbkh LMeysCyUJ1vBH1vUYGpP+WhZTUY8JOxnOFplw9Opr4IhkN+93U8Y5f2Wici8ZmFM+iA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=tipi-net.de; spf=pass smtp.mailfrom=tipi-net.de; dkim=pass header.d=tipi-net.de header.i=@tipi-net.de header.a=rsa-sha256 header.s=dkim header.b=oN0n3S4G; arc=none smtp.remote-ip=194.13.80.246 Received: from mail.tipi-net.de (mail.tipi-net.de [194.13.80.246]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C57B606A31A; Fri, 30 Oct 2026 19:33:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6C57B606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=tipi-net.de header.i=@tipi-net.de header.a=rsa-sha256 header.s=dkim header.b=oN0n3S4G Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id C6F0BA12EB; Fri, 30 Oct 2026 20:33:13 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1793388800; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=QtGA4oygWFl5CX8vg4imBuTm2I065I8hD6TIKVaKg5Q=; b=oN0n3S4Gd2LVGtKCDgtH54i2pOhilG/jMIpjCCAbd3+LpXofGFf61vIwpzBwcPREbEm7an p36ug+Vmik11e0AUTxf2NB1yqnHB4rwsnODkaL8EL2UbcvZU3CHWaxhC+neli9Zp9dfxlD btxU5LaG2pvvU9A8D7RiZyM3xNlZHkH9KfGP8aI4/N6owHRlg2hxePioLhy5eoVvTdabdE bK0stGfaC953F3oRg4QwmORBbTF4u/pCuXaBsSo5tYEXb6scv2o3bpyqX4lzrM+lIAeRpy aCYoEn1Hu6NiXRxuyfTYeH0C9anNwX5JSuXWI5QjsnWeABE2TksgvkP93INtIQ== Message-ID: <3eb9f731c0facedbadfcba6ae490862e7f6e3fd1.camel@tipi-net.de> Subject: Re: [PATCH net] net: stmmac: Clear DMA errors for multi-channel interrupts From: Nicolai Buchwitz To: Maxime Chevallier , Andrew Lunn , Jakub Kicinski , davem@davemloft.net, Eric Dumazet , Paolo Abeni , Simon Horman , Maxime Coquelin , Alexandre Torgue , Russell King , Lorenzo Bianconi , Ovidiu Panait Cc: thomas.petazzoni@bootlin.com, Alexis =?ISO-8859-1?Q?Lothor=E9?= , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Date: Fri, 30 Oct 2026 20:33:12 +0100 In-Reply-To: <20261030102251.208929-1-maxime.chevallier@bootlin.com> References: <20261030102251.208929-1-maxime.chevallier@bootlin.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2-9 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Last-TLS-Session-Version: TLSv1.3 On Fri, 2026-10-30 at 11:22 +0100, Maxime Chevallier wrote: > The Multi-MSI interrupt handler doesn't clear the DMA error > interrupts, > and this leads to interrupt storms when one of these interrupts > starts > firing : >=20 > =C2=A0- The RBU (rx buff unav) which triggers under high traffic load >=20 > =C2=A0=C2=A0 This triggers easily with iperf3 and small udp packets, and = shows > =C2=A0=C2=A0 when running the netpoll kselftest >=20 > =C2=A0- The RPS (rx process stop) which triggers when we stop the DMA RX. >=20 > =C2=A0=C2=A0 This one shows when restarting the RX logic without doing a > down/up > =C2=A0=C2=A0 cycle, like when attaching an XDP program. The XSK kselftest= s > =C2=A0=C2=A0 triggers it. >=20 > Let's make sure we clear these interrupts for multi-MSI cases. It's > already properly done for the single-chan interrupt, and for that > introduce an "ERR" DMA dir, as we don't want to touch the RI/TI bits > when handling these interrupts. >=20 > To avoid duplication, the DMA TX error handling is factored out in a > dedicated helper (in the same commit to ease backporting). >=20 > Both of the above storms have been found on dwmac-motorcomm (YT8601), > and are triggered by the xdp.py, xsk_reconfig.py, xdp_features.py, > ring_reconfig.py and netpoll_basic kernel selftests. >=20 > This seems to only affect dwmac4, there's no multi-msi mode on > dwmac1000, and on dwxgmac these interrupts are masked as of today. >=20 > Fixes: 6ccf12ae111e ("net: stmmac: use interrupt mode INTM=3D1 for > multi-MSI") > Signed-off-by: Maxime Chevallier > --- > [..,] Reviewed-by: Nicolai Buchwitz thanks, Nicolai --=20 Nicolai Buchwitz