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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 849CFC433DB for ; Mon, 1 Feb 2021 18:54:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4759764E8F for ; Mon, 1 Feb 2021 18:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231622AbhBASyq (ORCPT ); Mon, 1 Feb 2021 13:54:46 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24517 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229996AbhBASyp (ORCPT ); Mon, 1 Feb 2021 13:54:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612205599; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XQVROIJBZJimrNT5zujh9c6zhxtdo4MhqtcVHix96uQ=; b=L/JiauS1+iDr2i3B/Op7PmzED1Qbo1xpOTRfw+xqLT5zeJ5xuax9nRydayr0nvLE118Kq7 R6/IT3FsgPGQ+aq+pWGHUMOwNRuluyV4Pq7QzZTjYvR4ci9nT0zVnm9FTJC6umtrOTDx4K 7CaH5jjdMqJqe0GqmJZjQke6ydR7sBc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-586-9Dp9ltqnO4-eI5e3B-1ctA-1; Mon, 01 Feb 2021 13:53:15 -0500 X-MC-Unique: 9Dp9ltqnO4-eI5e3B-1ctA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6AE11107ACE6; Mon, 1 Feb 2021 18:53:14 +0000 (UTC) Received: from localhost.localdomain (unknown [10.10.110.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2EF56614FC; Mon, 1 Feb 2021 18:53:13 +0000 (UTC) Message-ID: <408a5a3589c2acbe59824a8dbee8cbcd2afefbf4.camel@redhat.com> Subject: Re: [PATCH net-next 3/3] net: mhi: Add mbim proto From: Dan Williams To: Loic Poulain Cc: Jakub Kicinski , David Miller , Network Development , Carl =?UTF-8?Q?Yin=28=E6=AE=B7=E5=BC=A0=E6=88=90=29?= , =?ISO-8859-1?Q?Bj=F8rn?= Mork Date: Mon, 01 Feb 2021 12:53:12 -0600 In-Reply-To: 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> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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