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=-5.7 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 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 9C617C433DB for ; Mon, 1 Feb 2021 12:14:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 491EE64EA0 for ; Mon, 1 Feb 2021 12:14:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231252AbhBAMON (ORCPT ); Mon, 1 Feb 2021 07:14:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229787AbhBAMOI (ORCPT ); Mon, 1 Feb 2021 07:14:08 -0500 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DAF6C061756 for ; Mon, 1 Feb 2021 04:13:27 -0800 (PST) Received: by mail-pf1-x42f.google.com with SMTP id w18so11435943pfu.9 for ; Mon, 01 Feb 2021 04:13:27 -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; bh=PQKa0QbKtMZtWsNJ8J3oY3JodpMQf8nMPv8lfKSosC4=; b=J47QIGJX20a07kPVr7Jg8VvUq0WIyppcjnP2ZYodc8HJYVgLkzSXzScnPznMicPfOF OzhTG+Xy2QZHZFlLJFY4I9CH7CdvNF/A93wbScWxz6FB25bx5eHB25gwx5w+tPMZskpk vy8UaCidgCrwRqNwAViM+BJOvT61sTaCBPZ1BH6nhj2n7SkfrWuQLzZgVEfwM8deXQyF wh6nO56FTLtU84uxjZbojFCN7T7NPrBVDPbTerDzqgb7KPqDHYZlHE0T1OBV7eVkILSA 7ftjV8JAo+Y57GjeJn56ss3MuDITY8xwbINnJzDd/AhKWWFtDVJ1mgxm/Ybbmr+qKpiV Tiiw== 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; bh=PQKa0QbKtMZtWsNJ8J3oY3JodpMQf8nMPv8lfKSosC4=; b=rGx+J7T5Vf14jWALFzfv6aM05JQRVgMn1QghTjfGy3o849PULrtf17WsuidRLDL/pd Bez1I3DLNDSQE5TxNM7itw+WyKjgb7o9+URsoM0HCIzdCQmnjvzKC/hTdRhHIpX1RDjd Yib+AfTt/h5IVLFfC+U6hf1m0TBIErGLAeleue46sJlNA0uUD6AbQ95pVQctia1OJGJ+ CVPFnwOPglAP8jg76ISiBoG5CZNO/2OpuJMnYinOP5fdy4F2tBx4qoebguqRsMplxkPJ r+ir0c/x3KQSfrLxvIUo0FzxopXjiksCPwMrDyjVX7yOx/ljrb2zqdBgq5+ivOeg7Itx TAow== X-Gm-Message-State: AOAM5321raen5DnFgmZXEMg9I0SG96rXlWuojFq+Jj0Y7X3qZZ2wsNfs u70Ulh9NHw5FN+Ai32ZAqsAo X-Google-Smtp-Source: ABdhPJxvXtXtPNdQJBehzz4G4bByyyDTAZPIGymO4yZngY1PB57ITVWg6TzyGTycWLB0XmWgwwHCuQ== X-Received: by 2002:a62:7541:0:b029:1b9:c47e:7c14 with SMTP id q62-20020a6275410000b02901b9c47e7c14mr16865949pfc.30.1612181606880; Mon, 01 Feb 2021 04:13:26 -0800 (PST) Received: from thinkpad ([103.77.37.179]) by smtp.gmail.com with ESMTPSA id c204sm17329883pfc.152.2021.02.01.04.13.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Feb 2021 04:13:26 -0800 (PST) Date: Mon, 1 Feb 2021 17:43:22 +0530 From: Manivannan Sadhasivam To: Greg KH 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: <20210201121322.GC108653@thinkpad> References: <1609958656-15064-1-git-send-email-hemantk@codeaurora.org> <20210113152625.GB30246@work> <20210201105549.GB108653@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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! Thanks, Mani > thanks, > > greg k-h