From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 10E2CA052A; Wed, 27 Jan 2021 15:34:55 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 9F640140DD7; Wed, 27 Jan 2021 15:34:54 +0100 (CET) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by mails.dpdk.org (Postfix) with ESMTP id 60520140D68 for ; Wed, 27 Jan 2021 15:34:53 +0100 (CET) IronPort-SDR: icsKlJrgw7ppDBKNSbsKCgyr7pozn4EXIfoMCFX3G2fDkAOVCjGrDNG5DFNSw7UFoWKJ7Qeo5P 470sJ+62YkmA== X-IronPort-AV: E=McAfee;i="6000,8403,9876"; a="180154628" X-IronPort-AV: E=Sophos;i="5.79,379,1602572400"; d="scan'208";a="180154628" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2021 06:34:52 -0800 IronPort-SDR: DRx40g61dsfZwkfI2KYT3m+VCzLL1DA86U0jksKf7P08OS6yti0hhFCy62xIkcq+zRrERk17O4 CnmsxWWIGpcw== X-IronPort-AV: E=Sophos;i="5.79,379,1602572400"; d="scan'208";a="430117240" Received: from fyigit-mobl1.ger.corp.intel.com (HELO [10.213.208.215]) ([10.213.208.215]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2021 06:34:51 -0800 To: Liron Himi , Jerin Jacob Kollanukkaran Cc: "dev@dpdk.org" References: <20201202101212.4717-1-lironh@marvell.com> <20210122191925.24308-1-lironh@marvell.com> <20210122191925.24308-27-lironh@marvell.com> <78541fad-ec6d-401a-37c8-45df28e942b0@intel.com> From: Ferruh Yigit Message-ID: <6200e955-7a00-651a-2389-ad3756a8290a@intel.com> Date: Wed, 27 Jan 2021 14:34:47 +0000 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [EXT] Re: [PATCH v2 26/37] net/mvpp2: introduce fixup for fifo overrun X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 1/27/2021 2:08 PM, Liron Himi wrote: > > > Liron Himi > Staff Software Engineer > > > > Park Azorim, Kyriat Arie, Petah Tikva, 49527, Israel > Mobile: +972.52.3329169 > > -----Original Message----- > From: Ferruh Yigit > Sent: Wednesday, 27 January 2021 01:50 > To: Liron Himi ; Jerin Jacob Kollanukkaran > Cc: dev@dpdk.org > Subject: [EXT] Re: [dpdk-dev] [PATCH v2 26/37] net/mvpp2: introduce fixup for fifo overrun > > External Email > > ---------------------------------------------------------------------- > On 1/22/2021 7:19 PM, lironh@marvell.com wrote: >> From: Liron Himi >> >> Currently the HW is configured with only one pool which its buffer >> size may be larger than the rx-fifo-size. >> In that situation, frame size larger than the fifo-size is gets >> dropped due to fifo overrun. >> this is cause because the HW works in cut-through mode which waits to >> have in the fifo at least the amount of bytes as define in the >> smallest pool's buffer size. >> >> This patch add a dummy pool which its buffer size is very small >> (smaller than 64B frame). this tricks the HW and any frame size is >> gets passed from the FIFO to the PP2. >> >> Signed-off-by: Liron Himi > > so this is fixing the FIFO overrun, can you please provide the fixes line? > [L.H.] it is kind of combination of HW fifo size (which defined by kernel driver), given buffer size and incoming pkt size. I don't think I can point to a line in DPDK driver code that this patch is fixing. > it is a kind of WA for a HW issue. > Is HW FIFO size or HW behavior (to wait at least smallest pool's buffer size) changed with recent kernel driver or MUSDK to cause this problem? If so can you please mention/reference that change in the commit log? > And should this patch backported? > [L.H.] it cannot be backported as it depends on MUSDK api change. > Is the fix or problem depends on the MUSDK API change? If the fix has a dependency will this be a problem, since it means latest driver won't be usable with old MUSDK version? Can you please clarify the dependency in the commit log? Thanks, ferruh