From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [148.163.129.52]) by dpdk.org (Postfix) with ESMTP id 395031D039 for ; Sat, 9 Jun 2018 12:11:57 +0200 (CEST) X-Virus-Scanned: Proofpoint Essentials engine Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1-us1.ppe-hosted.com (Proofpoint Essentials ESMTP Server) with ESMTPS id C9637940054; Sat, 9 Jun 2018 10:11:54 +0000 (UTC) Received: from [192.168.38.17] (84.52.114.114) by ukex01.SolarFlarecom.com (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1044.25; Sat, 9 Jun 2018 11:11:49 +0100 To: Ferruh Yigit , Neil Horman , John McNamara , "Marko Kovacevic" , Thomas Monjalon CC: References: <20180608225709.19473-1-ferruh.yigit@intel.com> From: Andrew Rybchenko Message-ID: <75ca3e7f-9241-309f-c2ce-5c01f65bfdf9@solarflare.com> Date: Sat, 9 Jun 2018 13:11:45 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180608225709.19473-1-ferruh.yigit@intel.com> Content-Language: en-GB X-Originating-IP: [84.52.114.114] X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To ukex01.SolarFlarecom.com (10.17.10.4) X-TM-AS-Product-Ver: SMEX-11.0.0.1191-8.100.1062-23896.003 X-TM-AS-Result: No--5.599100-0.000000-31 X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-MDID: 1528539116-qhPzGAQbKQJ2 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [RFC] ethdev: add new offload flag to keep CRC X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Jun 2018 10:11:57 -0000 On 06/09/2018 01:57 AM, Ferruh Yigit wrote: > DEV_RX_OFFLOAD_KEEP_CRC offload flag added. > > DEV_RX_OFFLOAD_CRC_STRIP flag will remain one more release > default behavior in PMDs is to keep the CRC until this flag removed > > Until DEV_RX_OFFLOAD_CRC_STRIP flag is removed: > - Setting both KEEP_CRC & CRC_STRIP is INVALID ethdev layer should enforce it. > - Setting only CRC_STRIP PMD should strip the CRC > - Setting only KEEP_CRC PMD should keep the CRC > - Not setting both PMD should keep the CRC > > Signed-off-by: Ferruh Yigit - rte_rx_offload_names should be updated as well - testpmd should be updated I'm not sure that I understand the transition plan. I think PMDs which support KEEP_CRC should be updated by the patch to advertise the offload. Otherwise, generic checks in ethdev will not allow to enable it. Other option is to simply drop it on ethdev layer (since basically it changes nothing for PMD now) and encourage PMD maintainers to advertise and take it into account if the feature is supported (however, if the bit is dropped on ethdev layer, the code would be unused/dead regardless application request). Too complicated. I guess there are not so many PMDs which support KEEP_CRC. Better to update them. The patch should encourage applications which would like to keep CRC to use the offload since the next release will drop CRC_STRIP and it will change behaviour (no KEEP_CRC => strip it)