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=-7.2 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,URIBL_BLOCKED,USER_AGENT_SANE_1 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 33488C433DB for ; Tue, 2 Feb 2021 04:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D35364ED9 for ; Tue, 2 Feb 2021 04:23:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231673AbhBBEW5 (ORCPT ); Mon, 1 Feb 2021 23:22:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231420AbhBBEWx (ORCPT ); Mon, 1 Feb 2021 23:22:53 -0500 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF4BBC06174A for ; Mon, 1 Feb 2021 20:22:13 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id j2so12402746pgl.0 for ; Mon, 01 Feb 2021 20:22:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=OnQNkjd4mkQ0QEf+L9w3boF0r8eBsim5MI3JySRYCIY=; b=IgxxB1ECYY6bdi3/vyvUj+1qNPMZSm6A3LWV3SzdJaVmt5wIEhpD0GZ19hPybannd4 F0QNDL78kipKtbyieGWmYhPAZjTvmK/TETYFpBQMIChPgFzX/mnGevZi+Nku/flyzs0O BS9ZPfogMkuiYW+w+TBw8ULTNclfRqaTctWGTh5F486pI68hOPDwrYBVmJbSL/kyzLl7 2qG320B/vQvbIdPja8iz3DGTkXk2a5ckoilKAXeffpzuX+o5TTZ4c/Nk4BZKXUmtZONm 3sfYoqeQdJPMqDb3WeNIMwpy5hAprYh5S5riFIgJ/3Q37PEJYSQJECedK0lTJDFfwTcQ ly3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=OnQNkjd4mkQ0QEf+L9w3boF0r8eBsim5MI3JySRYCIY=; b=Z9eeYNUM4gGl+TdyoSseyTmJtypzGclkOyBOBZtxyW+ZqC88vj2TD84mS6dnaE8hsm dfRM2XuxWpBe7LI6cvpd/SJ6MTDgqwqSGMY06fNbGhOuWo71DiHk+bJpP4gHZAi1AbgW 9k3+/sJl8OD1RMwpElDWXmkYppk9MP4x9Hyr0LxdCptA4hKmSrXL0RN9K68Vpj5RgRnp DWZwX7pMlyyzSJc4Ry7uKhP5OJBnXGw2FVbTZ5OneSeQtCcCaRmPxRq6cVOfK2MpfNOV 5h6jM2ayaj83O7XC3+MmZRnikSarSMHgNBWFprL9mThyR7H+lO42jXL6hTd6VkSXpIUS KvYA== X-Gm-Message-State: AOAM531tQLLFYXte9Pr72q6GAjbMclmKhfXbJKbkl9Uy8h7nTf6Fua/0 qRATjT97PJsccQGhnHT23ikq X-Google-Smtp-Source: ABdhPJxRDatZuxShf8dlB06+K8ASIaZrRN6JhfmDDLfhQjs8wFb5RXC92dCMPI7kn+QvQwOyshYHMA== X-Received: by 2002:aa7:9f95:0:b029:1be:aeed:9672 with SMTP id z21-20020aa79f950000b02901beaeed9672mr19960994pfr.54.1612239733159; Mon, 01 Feb 2021 20:22:13 -0800 (PST) Received: from work ([103.77.37.138]) by smtp.gmail.com with ESMTPSA id 14sm20011747pfy.55.2021.02.01.20.22.09 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 01 Feb 2021 20:22:12 -0800 (PST) Date: Tue, 2 Feb 2021 09:52:08 +0530 From: Manivannan Sadhasivam To: Greg KH , kuba@kernel.org, davem@davemloft.net Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, jhugo@codeaurora.org, bbhatt@codeaurora.org, loic.poulain@linaro.org, netdev@vger.kernel.org Subject: Re: [RESEND PATCH v18 0/3] userspace MHI client interface driver Message-ID: <20210202042208.GB840@work> References: <1609958656-15064-1-git-send-email-hemantk@codeaurora.org> <20210113152625.GB30246@work> <20210201105549.GB108653@thinkpad> <20210201121322.GC108653@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210201121322.GC108653@thinkpad> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org + Jakub, Dave On Mon, Feb 01, 2021 at 05:43:22PM +0530, Manivannan Sadhasivam wrote: > On Mon, Feb 01, 2021 at 12:15:51PM +0100, Greg KH wrote: > > On Mon, Feb 01, 2021 at 04:25:49PM +0530, Manivannan Sadhasivam wrote: > > > Hi Greg, > > > > > > On Wed, Jan 27, 2021 at 04:15:42PM +0100, Greg KH wrote: > > > > On Wed, Jan 13, 2021 at 08:56:25PM +0530, Manivannan Sadhasivam wrote: > > > > > Hi Greg, > > > > > > > > > > On Wed, Jan 06, 2021 at 10:44:13AM -0800, Hemant Kumar wrote: > > > > > > This patch series adds support for UCI driver. UCI driver enables userspace > > > > > > clients to communicate to external MHI devices like modem. UCI driver probe > > > > > > creates standard character device file nodes for userspace clients to > > > > > > perform open, read, write, poll and release file operations. These file > > > > > > operations call MHI core layer APIs to perform data transfer using MHI bus > > > > > > to communicate with MHI device. > > > > > > > > > > > > This interface allows exposing modem control channel(s) such as QMI, MBIM, > > > > > > or AT commands to userspace which can be used to configure the modem using > > > > > > tools such as libqmi, ModemManager, minicom (for AT), etc over MHI. This is > > > > > > required as there are no kernel APIs to access modem control path for device > > > > > > configuration. Data path transporting the network payload (IP), however, is > > > > > > routed to the Linux network via the mhi-net driver. Currently driver supports > > > > > > QMI channel. libqmi is userspace MHI client which communicates to a QMI > > > > > > service using QMI channel. Please refer to > > > > > > https://www.freedesktop.org/wiki/Software/libqmi/ for additional information > > > > > > on libqmi. > > > > > > > > > > > > Patch is tested using arm64 and x86 based platform. > > > > > > > > > > > > > > > > This series looks good to me and I'd like to merge it into mhi-next. You > > > > > shared your reviews on the previous revisions, so I'd like to get your > > > > > opinion first. > > > > > > > > If you get the networking people to give you an ack on this, it's fine > > > > with me. > > > > > > > > > > As discussed in previous iteration, this series is not belonging to networking > > > subsystem. The functionality provided by this series allows us to configure the > > > modem over MHI bus and the rest of the networking stuff happens over the > > > networking subsystem as usual. > > > > Great, then it should be easy to get their acceptance :) > > > > > This holds the same with USB and serial modems which we are having over decades > > > in mainline. > > > > I don't see the connection here, sorry. > > > > For instance USB_NET_CDC_MBIM driver creates the /dev/cdc-wdmX chardev node for > configuring the modems which supports MBIM protocol over USB. Like that, this > driver creates /dev/mhiX_MBIM chardev node for configuring the modem over MHI > bus instead of USB. The question arised why we are creating a chardev node for > each supported configuration (channels in the case of MHI) and why can't we use > the existing /dev/cdc-wdmZ interfaces? The anwser is there is no standard > subsystem for WWAN and all the drivers represent a chardev which gets used by > the userspace tools such a Network manager for establishing connection. > > And /dev/cdc-wdmX is restricted to the USB CDC devices. > > Hope this clarifies! > Jakub, Dave, Adding you both to get your reviews on this series. I've provided an explanation above and in the previous iteration [1]. Thanks, Mani [1] https://lkml.org/lkml/2020/12/12/16 > Thanks, > Mani > > > thanks, > > > > greg k-h