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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 123FBC83F12 for ; Mon, 28 Aug 2023 10:19:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230494AbjH1KSk (ORCPT ); Mon, 28 Aug 2023 06:18:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231146AbjH1KSO (ORCPT ); Mon, 28 Aug 2023 06:18:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEB84107 for ; Mon, 28 Aug 2023 03:18:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9FE2E6374C for ; Mon, 28 Aug 2023 10:18:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5D0FC433C9; Mon, 28 Aug 2023 10:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693217886; bh=g/ha3i/XAUI8wyeoN5V828zHHPWvFHVNaqZ3/xQjpBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rOpJmJ9BOUTEsGuXJWy01Fytm/KpwwKmHN7dWm4znHG/rN0AatHb5CBkPtyfXz0ew xcyWZRjSVm9EYk6t8ObdLkRTgc0Fcrxw7K3VtDF0xYnrrk68p1a+TapbaY69BydbxK 3JCNm7nHUp9EcLHdoq4+rWacE9YDud9kgjtbyxwE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vladimir Oltean , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.4 018/129] net: dsa: felix: fix oversize frame dropping for always closed tc-taprio gates Date: Mon, 28 Aug 2023 12:11:37 +0200 Message-ID: <20230828101157.998306636@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101157.383363777@linuxfoundation.org> References: <20230828101157.383363777@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vladimir Oltean [ Upstream commit d44036cad31170da0cb9c728e80743f84267da6e ] The blamed commit resolved a bug where frames would still get stuck at egress, even though they're smaller than the maxSDU[tc], because the driver did not take into account the extra 33 ns that the queue system needs for scheduling the frame. It now takes that into account, but the arithmetic that we perform in vsc9959_tas_remaining_gate_len_ps() is buggy, because we operate on 64-bit unsigned integers, so gate_len_ns - VSC9959_TAS_MIN_GATE_LEN_NS may become a very large integer if gate_len_ns < 33 ns. In practice, this means that we've introduced a regression where all traffic class gates which are permanently closed will not get detected by the driver, and we won't enable oversize frame dropping for them. Before: mscc_felix 0000:00:00.5: port 0: max frame size 1526 needs 12400000 ps, 1152000 ps for mPackets at speed 1000 mscc_felix 0000:00:00.5: port 0 tc 0 min gate len 1000000, sending all frames mscc_felix 0000:00:00.5: port 0 tc 1 min gate len 0, sending all frames mscc_felix 0000:00:00.5: port 0 tc 2 min gate len 0, sending all frames mscc_felix 0000:00:00.5: port 0 tc 3 min gate len 0, sending all frames mscc_felix 0000:00:00.5: port 0 tc 4 min gate len 0, sending all frames mscc_felix 0000:00:00.5: port 0 tc 5 min gate len 0, sending all frames mscc_felix 0000:00:00.5: port 0 tc 6 min gate len 0, sending all frames mscc_felix 0000:00:00.5: port 0 tc 7 min gate length 5120 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 615 octets including FCS After: mscc_felix 0000:00:00.5: port 0: max frame size 1526 needs 12400000 ps, 1152000 ps for mPackets at speed 1000 mscc_felix 0000:00:00.5: port 0 tc 0 min gate len 1000000, sending all frames mscc_felix 0000:00:00.5: port 0 tc 1 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS mscc_felix 0000:00:00.5: port 0 tc 2 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS mscc_felix 0000:00:00.5: port 0 tc 3 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS mscc_felix 0000:00:00.5: port 0 tc 4 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS mscc_felix 0000:00:00.5: port 0 tc 5 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS mscc_felix 0000:00:00.5: port 0 tc 6 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS mscc_felix 0000:00:00.5: port 0 tc 7 min gate length 5120 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 615 octets including FCS Fixes: 11afdc6526de ("net: dsa: felix: tc-taprio intervals smaller than MTU should send at least one packet") Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230817120111.3522827-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/dsa/ocelot/felix_vsc9959.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index ca69973ae91b9..b1ecd08cec96a 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -1081,6 +1081,9 @@ static u64 vsc9959_tas_remaining_gate_len_ps(u64 gate_len_ns) if (gate_len_ns == U64_MAX) return U64_MAX; + if (gate_len_ns < VSC9959_TAS_MIN_GATE_LEN_NS) + return 0; + return (gate_len_ns - VSC9959_TAS_MIN_GATE_LEN_NS) * PSEC_PER_NSEC; } -- 2.40.1