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 26E04C4167B for ; Sat, 12 Dec 2020 06:10:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E43B523B85 for ; Sat, 12 Dec 2020 06:10:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438343AbgLLGJW (ORCPT ); Sat, 12 Dec 2020 01:09:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407150AbgLLGJK (ORCPT ); Sat, 12 Dec 2020 01:09:10 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38E5BC0613D6 for ; Fri, 11 Dec 2020 22:08:30 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id t8so8425335pfg.8 for ; Fri, 11 Dec 2020 22:08:30 -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=KrrfqCz8fMnvHaHUpeYSii56XdL30O9rReJj2B9MO5Y=; b=DH8VhTet2wSm66pWTT6sexa+GKrsgAa2RZ0lUe0rK0qB6wJxrl1bQr9rsi5lLJCzMP t4nZHGk77JTx4s6KVuGSWBp1sslP+rME+kYcDZ6jWZ4jOKUEExRCWSSqvoQd7DFmElKq L7aa3IubZ3zPnTuYWOMkG+DNfhzorJdgQ1LvqBmXTzDjBAODiZ4BBuPDRoNUoQw5mbew PHHFQhRsdAGvATgjKIiOpzwEaYg5Mxq9Z2FVhVbYpcuoWTVpttRHH7fJ6fskxfhSECwb hsbirvv+SPX74C9hR1ILC6yvK7KgeW60LUXWL3Cdq/dq1MMnTmn6VfgUenz//5bdoe64 tibQ== 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=KrrfqCz8fMnvHaHUpeYSii56XdL30O9rReJj2B9MO5Y=; b=OqVmO04n03T1DX6enT/e1df3d5+x+ldoEFwF+xcdzOciu5anrJpOxh5aDEh11dKqa/ CewO36BmCMGxxf8ZcnWOb0iiBRfNV7xVFBJwxu1qSxoWwRyG4fKLTIZCICYNZjUlX5h5 cbzSAf4fevtAwarcV7YlY6ZKIihUVsnCLyz3L2d1jzVgbkRPu1KD3FXiFJO4WhXZUKgC 8kw+ANrEJLOva94ni2hqy/sNVDhq0MlzYRuQVbmG11CrUwlofa3YFHLENZYIb2h0VEdS vmepBOU+D0xd4YflUQqTYCvkiSYb9FrMgxXgh7/PSs6YG24gfbTjv3qmmBNo/nMuNius jlaA== X-Gm-Message-State: AOAM5312bW/Z6dd7E7QbTOwEdD+quBea0+sKOtbzFfGzuJqUYMa4cgdZ BlDlONY52nefnVW1rdli7cTZ X-Google-Smtp-Source: ABdhPJxwXDciFcLMkVrR5J7z51OStwNUkEuuN0hATLH7Py2x7sV4BQHTyoPurCogWeN5lfufW6Ht0Q== X-Received: by 2002:a63:7982:: with SMTP id u124mr15124116pgc.259.1607753309565; Fri, 11 Dec 2020 22:08:29 -0800 (PST) Received: from thinkpad ([103.59.133.81]) by smtp.gmail.com with ESMTPSA id v19sm12299536pjg.50.2020.12.11.22.08.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Dec 2020 22:08:28 -0800 (PST) Date: Sat, 12 Dec 2020 11:38:18 +0530 From: Manivannan Sadhasivam To: Jakub Kicinski Cc: Dan Williams , Greg KH , Hemant Kumar , 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: [PATCH v17 3/3] bus: mhi: Add userspace client interface driver Message-ID: <20201212060818.GA10816@thinkpad> References: <1607670251-31733-1-git-send-email-hemantk@codeaurora.org> <1607670251-31733-4-git-send-email-hemantk@codeaurora.org> <81dfd08b90f841194237e074aaa3d57cada7afad.camel@redhat.com> <20201211200816.7062c3f9@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201211200816.7062c3f9@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Dec 11, 2020 at 08:08:16PM -0800, Jakub Kicinski wrote: > On Fri, 11 Dec 2020 11:37:34 -0600 Dan Williams wrote: > > Just to re-iterate: QMI ~= AT commands ~= MBIM (not quite, but same > > level) > > > > We already do QMI-over-USB, or AT-over-CDC-ACM. This is QMI-over-MHI. > > Why do we need a different QMI-over-X for every X? If you say there > are already chardev interfaces to configure WWAN why not provide one > of those? > Just because the underlying PHY is different and it offers more services than just configuring the modem (downloading crash dump, firmware download etc...) The existing chardev nodes are closely tied to the physical interfaces. For instance, /dev/cdc_wdm is used by the USB based WWAN devices. So we really can't reuse it for MHI/PCIe. > > It's not networking data plane. It's WWAN device configuration. > > Ack. Not that network config doesn't fall under networking, but eh. > I wonder - did DaveM ever ack this, or was it just out of his sight > enough, behind the cdev, to never trigger a nack? > > > There are no current kernel APIs for this, and I really don't think we > > want there to be. The API surface is *huge* and we definitely don't > > want that in-kernel. > > It is what it is today for WWAN. I don't think anyone in the > development community or among users is particularly happy about > the situation. Which makes it rather self evident why there is > so much apprehension about this patch set. It's going to be > a user space channel for everything Qualcomm - AI accelerator etc. > Widening the WWAN status quo to more device types. Well not everything Qualcomm but for just the subsystems where there is no standardization right now. I think we went too far ahead for standardizing the modems. Thanks, Mani