From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B6F176034; Thu, 11 Jul 2024 18:22:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720722159; cv=none; b=YJDBr31msZLj49i4/5kSlteMq+3EBDFxXv1Y92u1ppp8Ql9+Wg5up1zTzUlQINU9l1gFqJx7zpOR/iN/nzh/6bgqjzpQnvPNezxX76X+0y6aFX3BvAjzp7YjtwjXZz4xebnsYlXH2isioIZT0GRlNZPaayqKsXgK15drp/3lJfM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720722159; c=relaxed/simple; bh=rwRq5sHZuJi1yLF7Y67zhwSlLDwgpG63WbjsUOAnJro=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ikJXl9kjHebVOkGN8k63+zvyJ2SA9VzFLomX8wC8QV7mFiBd9ty2+gMBD9FjA9jI9Ubhde4IEiXD4t9WNBMXD36jeRX0G8iylxagXxP5myRVMmt1wb6Ph2oKoQ9M+m4uaeZ1lYxVlss/l3CocuxhmqolXZxjCgRV5EiP4UsUhE4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=WZYIPrUS; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="WZYIPrUS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1720722158; x=1752258158; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=rwRq5sHZuJi1yLF7Y67zhwSlLDwgpG63WbjsUOAnJro=; b=WZYIPrUSYhHbUQTe848HnU9UXqCIW9wQaR7Lyn65Gn1Tk6HyzFbUES+x JTTosFhSFkmnfimpD5dqaMkD5ikZmoLq4AmW1jkiT5RihX4ayxIvHPjxi SULPq7j8dElRdGsxRIZbHbDoHYOW8paxiL71CTjCC/fNWtnbCK33VV0su OyhGAmpxADhtnp9FU01cdYcJrkDXIn9beQtgzNX1i47TV7KKD9sw9pWTR 1F+HC0hgam0Bhxy8tW4FWQrlaNQhyR4RXyYbPk1k1lY41GjLdwaE1wp8H SyDHI1XBgyS6wvd4U3yMKVzkaTId5xf02+293qw9xmqrHysAtAWlLg58t g==; X-CSE-ConnectionGUID: M2cZTRTJQlmNmQ8CNguZiQ== X-CSE-MsgGUID: nQftZ2UESeqD1ql7Wg2eiA== X-IronPort-AV: E=McAfee;i="6700,10204,11130"; a="29541743" X-IronPort-AV: E=Sophos;i="6.09,200,1716274800"; d="scan'208";a="29541743" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2024 11:22:27 -0700 X-CSE-ConnectionGUID: nOfmpfp9Qe2U/rAbMkJAbQ== X-CSE-MsgGUID: bhYsYfL6SzaAPuz4kI4/wA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,200,1716274800"; d="scan'208";a="53244456" Received: from unknown (HELO vcostago-mobl3) ([10.241.225.92]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2024 11:22:27 -0700 From: Vinicius Costa Gomes To: Faizal Rahim , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jesse Brandeburg , Tony Nguyen , Paul Menzel Cc: intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Faizal Rahim Subject: Re: [PATCH iwl-net v2 1/1] igc: Fix packet still tx after gate close by reducing i226 MAC retry buffer In-Reply-To: <20240706153807.3390950-1-faizal.abdul.rahim@linux.intel.com> References: <20240706153807.3390950-1-faizal.abdul.rahim@linux.intel.com> Date: Thu, 11 Jul 2024 11:22:26 -0700 Message-ID: <87h6cvss9p.fsf@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Faizal Rahim writes: > Testing uncovered that even when the taprio gate is closed, some packets > still transmit. > > According to i225/6 hardware errata [1], traffic might overflow the > planned QBV window. This happens because MAC maintains an internal buffer, > primarily for supporting half duplex retries. Therefore, even when the > gate closes, residual MAC data in the buffer may still transmit. > > To mitigate this for i226, reduce the MAC's internal buffer from 192 bytes > to the recommended 88 bytes by modifying the RETX_CTL register value. > > This follows guidelines from: > [1] Ethernet Controller I225/I22 Spec Update Rev 2.1 Errata Item 9: > TSN: Packet Transmission Might Cross Qbv Window > [2] I225/6 SW User Manual Rev 1.2.4: Section 8.11.5 Retry Buffer Control > > Note that the RETX_CTL register can't be used in TSN mode because half > duplex feature cannot coexist with TSN. > > Test Steps: > 1. Send taprio cmd to board A: > tc qdisc replace dev enp1s0 parent root handle 100 taprio \ > num_tc 4 \ > map 3 2 1 0 3 3 3 3 3 3 3 3 3 3 3 3 \ > queues 1@0 1@1 1@2 1@3 \ > base-time 0 \ > sched-entry S 0x07 500000 \ > sched-entry S 0x0f 500000 \ > flags 0x2 \ > txtime-delay 0 > > Note that for TC3, gate should open for 500us and close for another > 500us. > > 3. Take tcpdump log on Board B. > > 4. Send udp packets via UDP tai app from Board A to Board B. > > 5. Analyze tcpdump log via wireshark log on Board B. Ensure that the > total time from the first to the last packet received during one cycle > for TC3 does not exceed 500us. > > Signed-off-by: Faizal Rahim > --- > v1: https://patchwork.kernel.org/project/netdevbpf/patch/20240701100058.3301229-1-faizal.abdul.rahim@linux.intel.com/ > > Changelog: > v1 -> v2 > - Update commit description (Paul). > - Rename qbvfullth -> qbvfullthreshold (Paul). > --- Looks fine. Acked-by: Vinicius Costa Gomes Cheers, -- Vinicius