From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smartserver.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by dpdk.org (Postfix) with ESMTP id 0A84D8E9E for ; Tue, 15 Sep 2015 09:33:31 +0200 (CEST) X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Tue, 15 Sep 2015 09:33:24 +0200 Message-ID: <98CBD80474FA8B44BF855DF32C47DC358AF3BF@smartserver.smartshare.dk> In-Reply-To: <5061522.mAytVLfEX7@xps13> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [dpdk-dev] [PATCH v4 0/2] ethdev: add port speed capability bitmap Thread-Index: AdDvhQ/zAPNzZIieRwmSJ6AI/AUFsgAAQziQ References: <20150909131037.GA25122@autoinstall.dev.6wind.com> <98CBD80474FA8B44BF855DF32C47DC358AF3B7@smartserver.smartshare.dk> <5061522.mAytVLfEX7@xps13> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "Thomas Monjalon" , "Marc Sune" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH v4 0/2] ethdev: add port speed capability bitmap X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Sep 2015 07:33:31 -0000 Very valid question, Thomas. It's always a good idea to take a step back = and look at the bigger picture! Unfortunately, I can mention at least one company that has network = appliances in production using such low speeds, and even half duplex: = ours (SmartShare Systems). Basing our appliances on DPDK does not change = this situation. When you ship a lot of network appliances to a variety of customers, = some of the appliances will eventually end up at customers who connects = one of the ports to some equipment which is either very old, or which is = configured for forced speed/duplex due to their old IT policy which = hasn't been updated for decades. With a sufficient number customers, you = are going to see everything possible! Reality surpasses imagination. Med venlig hilsen / kind regards - Morten Br=F8rup -----Original Message----- From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]=20 Sent: 15. september 2015 09:05 To: Marc Sune Cc: Morten Br=F8rup; N=E9lio Laranjeiro; dev@dpdk.org; Olga Shern; = Adrien Mazarguil Subject: Re: [dpdk-dev] [PATCH v4 0/2] ethdev: add port speed capability = bitmap 2015-09-14 23:33, Marc Sune: > 2015-09-14 12:52 GMT+02:00 Morten Br=F8rup : > > This support function will be able to determine which speed is=20 > > higher when exotic speeds are added to the bitmap. Please extend=20 > > this conversion function to give three output parameters: speed,=20 > > full/half duplex, auto negotiation/non-auto negotiation, or add two=20 > > separate functions to get the duplex and auto-negotiation. >=20 > Since, Full/Half duplex is for legacy 10/100Mbps only (afaik), I have=20 > my doubts on using a bit for all speeds. I would suggest to define=20 > (unroll) 100M (or 100M_FD) and 100M_HD, and the same 10Mbps/1gbps, as=20 > Thomas was suggesting some mails ago. >=20 > This was done in v4 (implicitely 100M =3D=3D 100M_FD). See below. Are we going to use DPDK for such low speeds? Maybe we can remove half duplex modes? [...] > So, as of v4 of this patch, there could be: a) autoneg any supported=20 > speed (=3D> bitmap =3D=3D 0) b) autoneg over group of speeds (=3D> = more than=20 > one bit set in the bitmap) c) forced speed (one and only one set in = the bitmap). +1 [...] > * encode the link speed and duplex as of now, separating duplex and=20 > numeric speed. I would suggest to add the encoded speed+duplex bitmap=20 > flag for consistency (although redundant). > * or you return a single value, the bitmap with a single flag set of=20 > the unrolled speeds, and then have the helpers int=20 > rte_eth_speed_from_bm(int > val_bm) and bool rte_eth_duplex_from_bm(int val_bm). Who has already used half duplex mode with DPDK?