Date: Thu, 26 Feb 2015 08:21:41 -0600 From: Mike Karels <mike@karels.net> To: Hans Petter Selasky <hps@selasky.org> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, Eric Joyner <ricera10@gmail.com>, Jack Vogel <jfvogel@gmail.com>, "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org> Subject: Re: Adding new media types to if_media.h Message-ID: <201502261421.t1QELflw056051@mail.karels.net> In-Reply-To: Your message of Thu, 26 Feb 2015 10:39:02 %2B0100. <54EEE9B6.6090106@selasky.org>
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> I'm doing some work for Mellanox and we need some 100GBase types for > coming hardware products too. > I think we are not using the 32-bits of "ifm_media" well enough. > Has it been discussed to add more bits to "IFM_NMASK" and have more > ethernet types like IFM_ETHER_0, IFM_ETHER_1, IFM_ETHER_2, IFM_ETHER_3 .... > Currently 5 IFM types are defined. If 2 more bits can be added to > IFM_NMASK we have 5 bits total giving us 2**5 = 32 IFM types. Then it > should be possible to define "(32 - 5) * 32 = 864" more ethernet types, > which I think should be enough for now - or we add even one more bit to > IFM_NMASK ? Did you have specific bits in mind? I'm fairly sure they are all assigned to something now. The adjacent bits are used for the subtype/variant and options. Most of the options are used, maybe not all. I haven't checked whether the "instance" field is still used, though. It was for MII PHY numbers, I believe. If we had more bits, it seems better to put them directly into the subtype field rather than the type field. Mike
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