From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C34C8C433E0 for ; Mon, 1 Feb 2021 20:02:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 85DCB64EA2 for ; Mon, 1 Feb 2021 20:02:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233003AbhBAUCB (ORCPT ); Mon, 1 Feb 2021 15:02:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232970AbhBAUBe (ORCPT ); Mon, 1 Feb 2021 15:01:34 -0500 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BC90C061788 for ; Mon, 1 Feb 2021 12:00:53 -0800 (PST) Received: by mail-ej1-x634.google.com with SMTP id l9so26351758ejx.3 for ; Mon, 01 Feb 2021 12:00:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=f0tXe4AWrAn0r+44UyOKkZLPKxkqRxzW9CD7J1bYG6k=; b=Q4SQo+Jmw5A5MkCzT5/NrDVsVxnHJmtkxRIa+erLCJ+D8soAm8QEcmOHc7HhDDXHkL f1K/SGDS2wQvkVAhAfLbHynEDBacX5UKf7tUpTxttK9REoRxDe2j0sZRJxvXXgk4Vv1m zAewnkjM59Vh9nvZbseW8Ypf9Lay72QoEkdcnB+dZOGt0U1Swc76aI9Yv74f1b2PNdap 3LMkgHqxOYjS57fZxDUF9bX3Ww+vTn5/NY4uO+qxaNg1EqaimBxPCY2L4CZ5FOO3m3GJ e4dnpYtVtA3Cs9HZNXIdT1EGGbDi/6yZDSTX03/zekBvKshJ+CtKTPN/s4EfJTacC8Rw /ANQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=f0tXe4AWrAn0r+44UyOKkZLPKxkqRxzW9CD7J1bYG6k=; b=dwi1hCAN4R9HD0Rv/m9216Ed+a6mRvCK2AcfswKmTuLlSTHadH4fBg6lStOQZ1EJuU fC/Lq49bVLPX/jVanKEU80Qm8r3iM2mZw11seUgZVJ8PkT4S5gpf4IuqrtZGeO2U4naZ IgwTFbuNrJCvdiz4LkC/R6qY1NQWvYo9bnB8Y1hkMoYMsgIhM9xmDQqpenRmiSqO59OM grtZG1UuStAV3EdKKpWaAycrCJQpbMZRgUbcEub8KpBqC9dbo+HOF5KXEkDAaz3Jp3Oi Rj9NG6ZFn9iYscqmEypPak0g4JA3u/XYFRz4JWlIPuYzh1qi1my1OKz+eDDYezOCQwb3 w6bw== X-Gm-Message-State: AOAM533kjKEvrmK2eV+EcVi9zuFItNglV/IE2bnf3EF3ioeOkLTfDfkw rZ6ug4G63y19kr+EBzd4Z13jwC+esyS5qFwQ86Xs7w== X-Google-Smtp-Source: ABdhPJxnsK3shUePIHt+JO+OpiYVaQ//vWk6ZQzaF1AD3mpl8h9jv4/biHijtRU+3SXtYf6Db9inaVIGlxE6FXJGQeY= X-Received: by 2002:a17:907:a06f:: with SMTP id ia15mr19434321ejc.328.1612209651870; Mon, 01 Feb 2021 12:00:51 -0800 (PST) MIME-Version: 1.0 References: <1611766877-16787-1-git-send-email-loic.poulain@linaro.org> <1611766877-16787-3-git-send-email-loic.poulain@linaro.org> <20210129182108.771dc2fe@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <0bd01c51c592aa24c2dabc8e3afcbdbe9aa23bdc.camel@redhat.com> <408a5a3589c2acbe59824a8dbee8cbcd2afefbf4.camel@redhat.com> In-Reply-To: <408a5a3589c2acbe59824a8dbee8cbcd2afefbf4.camel@redhat.com> From: Loic Poulain Date: Mon, 1 Feb 2021 21:08:00 +0100 Message-ID: Subject: Re: [PATCH net-next 3/3] net: mhi: Add mbim proto To: Dan Williams Cc: Jakub Kicinski , David Miller , Network Development , =?UTF-8?B?Q2FybCBZaW4o5q635byg5oiQKQ==?= , =?UTF-8?Q?Bj=C3=B8rn_Mork?= Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 1 Feb 2021 at 19:53, Dan Williams wrote: > > On Mon, 2021-02-01 at 19:27 +0100, Loic Poulain wrote: > > On Mon, 1 Feb 2021 at 19:17, Dan Williams wrote: > > > On Fri, 2021-01-29 at 18:21 -0800, Jakub Kicinski wrote: > > > > On Wed, 27 Jan 2021 18:01:17 +0100 Loic Poulain wrote: > > > > > MBIM has initially been specified by USB-IF for transporting > > > > > data > > > > > (IP) > > > > > between a modem and a host over USB. However some modern modems > > > > > also > > > > > support MBIM over PCIe (via MHI). In the same way as > > > > > QMAP(rmnet), > > > > > it > > > > > allows to aggregate IP packets and to perform context > > > > > multiplexing. > > > > > > > > > > This change adds minimal MBIM support to MHI, allowing to > > > > > support > > > > > MBIM > > > > > only modems. MBIM being based on USB NCM, it reuses some > > > > > helpers > > > > > from > > > > > the USB stack, but the cdc-mbim driver is too USB coupled to be > > > > > reused. > > > > > > > > > > At some point it would be interesting to move on a factorized > > > > > solution, > > > > > having a generic MBIM network lib or dedicated MBIM netlink > > > > > virtual > > > > > interface support. > > > > > > What would a kernel-side MBIM netlink interface do? Just data- > > > plane > > > stuff (like channel setup to create new netdevs), or are you > > > thinking > > > about control-plane stuff like APN definition, radio scans, etc? > > > > Just the data-plane (mbim encoding/decoding/muxing). > > Ah yes :) If so, then fully agree. > > But is that really specific to MBIM? eg, same kinds of things happen > for QMI. Johannes referred to a more generic WWAN framework that we had > discussed 1.5+ years ago to address these issues. Might be worth > restarting that, perhaps simplifying, and figuring out the minimal set > of generic bits needed to describe/add/delete a data channel for WWAN > control protocols. > Dan > Right, it's not specific to MBIM, it would be just about decoupling protocol from transport (though MBIM is originally specified with USB transport). Having a WWAN framework/subsystem would indeed make sense, at least to structure the way all modems services/channels are exposed and grouped (today we have netdev, chardev, tty, etc) but it's far beyond this series, I'm not against restarting the discussion though. Regards, Loic