bitmap Reply-To: Shern <olgas at mellanox.com>, Adrien Mazarguil <adrien.mazarguil at 6wind.com> Bcc: Subject: Re: [dpdk-dev] [PATCH v4 0/2] ethdev: add port speed capability bitmap Reply-To: In-Reply-To: <20150909090855.GC17463 at autoinstall.dev.6wind.com>
Marc, On Tue, Sep 08, 2015 at 10:24:36PM +0200, Marc Sune wrote: > Neilo, > > 2015-09-08 12:03 GMT+02:00 N?lio Laranjeiro <nelio.laranjeiro at 6wind.com>: > > On Mon, Sep 07, 2015 at 10:52:53PM +0200, Marc Sune wrote: > > 2015-08-29 2:16 GMT+02:00 Marc Sune <marcdevel at gmail.com>: > > > > > The current rte_eth_dev_info abstraction does not provide any > mechanism > to > > > get the supported speed(s) of an ethdev. > > > > > > For some drivers (e.g. ixgbe), an educated guess can be done based on > the > > > driver's name (driver_name in rte_eth_dev_info), see: > > > > > > http://dpdk.org/ml/archives/dev/2013-August/000412.html > > > > > > However, i) doing string comparisons is annoying, and can silently > > > break existing applications if PMDs change their names ii) it does not > > > provide all the supported capabilities of the ethdev iii) for some > drivers > > > it > > > is impossible determine correctly the (max) speed by the application > > > (e.g. in i40, distinguish between XL710 and X710). > > > > > > This small patch adds speed_capa bitmap in rte_eth_dev_info, which is > > > filled > > > by the PMDs according to the physical device capabilities. > > > > > > v2: rebase, converted speed_capa into 32 bits bitmap, fixed alignment > > > (checkpatch). > > > > > > v3: rebase to v2.1. unified ETH_LINK_SPEED and ETH_SPEED_CAP into > > > ETH_SPEED. > > >? ? ?Converted field speed in struct rte_eth_conf to speeds, to allow a > > > bitmap > > >? ? ?for defining the announced speeds, as suggested by M. Brorup. > Fixed > > >? ? ?spelling issues. > > > > > > v4: fixed errata in the documentation of field speeds of rte_eth_conf, > and > > >? ? ?commit 1/2 message. rebased to v2.1.0. v3 was incorrectly based on > > >? ? ?~2.1.0-rc1. > > > > > > > Thomas, > > > > Since mostly you were commenting for v1 and v2; any opinion on this one? > > > > Regards > > marc > > Hi Marc, > > I have read your patches, and there are a few mistakes, for instance mlx4 > (ConnectX-3 devices) does not support 100Gbps. > > > When I circulated v1 and v2 I was kindly asking maintainers and reviewers of > the drivers to fix any mistakes in SPEED capabilities, since I was taking the > speeds from the online websites&catalogues. Some were fixed, but apparently > some were still missing. I will remove 100Gbps. Please circulate any other > error you have spotted. >From Mellanox website: - ConnectX-3 EN: 10/40/56Gb/s - ConnectX-3 Pro EN 10GBASE-T: 10G/s - ConnectX-3 Pro: EN 10/40/56GbE - ConnectX-3 Pro Programmable: 10/40Gb/s This PMD works with any of the ConnectX-3 adapters, so the announce speed should be 10/40/56Gb/s. > In addition, it seems your new bitmap does not support all kind of > speeds, take a look at the header of Ethtool, in the Linux kernel > (include/uapi/linux/ethtool.h) which already consumes 30bits without even > managing speeds above 56Gbps. > > > The bitmaps you are referring is SUPPORTED_ and ADVERTISED_. These bitmaps not > only contain the speeds but PHY properties (e.g. BASE for ETH). > > The intention of this patch was to expose speed capabilities, similar to the > bitmap SPEED_ in include/uapi/linux/ethtool.h, which as you see maps closely > to > ETH_SPEED_ proposed in this patch. > > I think the encoding of other things, like the exact model of the interface > and > its PHY details should go somewhere else. But I might be wrong here, so open > to > hear opinions. I understand the need to have capability fields, but I don't understand why you want to mix speeds and duplex mode in something which was previously only handling speeds. We now have redundant information in struct rte_eth_conf, whereas that structure has a speed field which embeds the duplex mode and a duplex field which does the same, which one should be used? > It would be nice to keep the field to represent the real speed of the > link, in case it is not represented by the bitmap, it could be also > useful for aggregated links (bonding for instance).? The current API > already works this way, it just needs to be extended from 16 to 32 bit > to manage speed above 64Gbps. > > > This patch does not remove rte_eth_link_get() API. It just changes the > encoding > of speed in struct rte_eth_link, to have an homogeneous set of constants with > the speed capabilities bitmap, as discussed previously in the thread (see > Thomas comments). IOW, it returns now a single SPEED_ value in the struct > rte_eth_link's link_speed field. You change the coding of the speed field, but applications still expect an integer, see port_infos_display function in app/test-pmd/config.c which directly uses printf on rte_eth_link.speed field, there are other places as well in PMDs (bn2x, bond, ...). This patch currently expects that everything uses a bitmap but it is not the case. I don't understand the need to change the rte_eth_link.speed field behavior to have the informations about the capability of the PHY, for this are two distinct things: - capability - speed and duplex negotiated (or not). I suggest to drop the part of the patch which changes the behavior of link_speed in struct rte_eth_link. PS: Sorry I did not sent the email as reply all. -- N?lio Laranjeiro 6WIND