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 5264AC433E0 for ; Wed, 3 Feb 2021 18:22:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0305E64E2B for ; Wed, 3 Feb 2021 18:22:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232927AbhBCSWD (ORCPT ); Wed, 3 Feb 2021 13:22:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232831AbhBCSWB (ORCPT ); Wed, 3 Feb 2021 13:22:01 -0500 Received: from mail-ed1-x536.google.com (mail-ed1-x536.google.com [IPv6:2a00:1450:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB65EC061786 for ; Wed, 3 Feb 2021 10:21:20 -0800 (PST) Received: by mail-ed1-x536.google.com with SMTP id y8so766413ede.6 for ; Wed, 03 Feb 2021 10:21:20 -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=m8wNkVQjjY9NrEsHNt1lfmAWPFTD4+i4OieQgWONqJs=; b=RsKoW3gSRDiwBP+hDKNnUSSrgnuP2rDLFh1WHXZWbc3xuVETCiZ78LVI8bdXyTaFO2 coLQIyv3iZQ3EOWc7Fi7KcTRtb9v4vNPQJTZ+Dm7umdriDuDVpCXFBu6PDAVN0KIdcoP G8KebZ0m9nK0HAa64YuucXx9GWtqM6lp6hPFeiElJ7xMNI4IZ1emzp83oesPjYwitLb5 9V3pYhmwRlRS15f28wj3/TjK5/1KxyH2MSaTfB4yz/d2NnKrgQT/7v9rxMU55wybc4Ju XBLH+CBGnKw8Q1JOoPJYYBIAfFUKRqkZAiUqiZpcPlkRf2RlIWB/yUFaYaaLJWwTwBlj F7EA== 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=m8wNkVQjjY9NrEsHNt1lfmAWPFTD4+i4OieQgWONqJs=; b=UtuSCQrASmTmA+BfPljjKoTcwOpNv4AQ4WDFSxmNIoUL0Kmjwy5oRqKFSgZwKruYAN EKyADEx5WolVhynQSEkn/PGn2feU7wd/cHLuf55O8NFuA7WZqL3IcSZKsSTTlZWNwq8A UCchgiN4nTIfzY5L4Ew8dP5bxQdM+6XnsEmnVRYOmpIzyQBoxq+qi/GK2JiulMvTOa3r kPGX7t2hyyHRICNBZOFLdbirMQNv+SBrnStsVlwsf5TblDQRS/9BqaJPAxjgj8LP77Sh MUIbzi0ok7AjJilV9YVOAb2rHSosHycirU3Kw57wSZWWy4b5Mh5066QRB5gwU0Ve2QfA MLBA== X-Gm-Message-State: AOAM532jx6qVA/wje5YAHjlAebTZ5gY2Mv5vXBKqX+1hAZZN3U7IY2Wi vyo/Qs7MI1mgfhwq79aNZzAAcJN3AHiEF58wbZ8+jw== X-Google-Smtp-Source: ABdhPJwCScNW96RHyG2xst74E//ExKGdIs09sTJ+ldXs2Lcc9gHDp9E4BK3S3tvxeVNlRXWjihFHFTQ5N1fl4YP94ww= X-Received: by 2002:aa7:c895:: with SMTP id p21mr4384983eds.165.1612376479543; Wed, 03 Feb 2021 10:21:19 -0800 (PST) MIME-Version: 1.0 References: <1609958656-15064-1-git-send-email-hemantk@codeaurora.org> <20210113152625.GB30246@work> <20210201105549.GB108653@thinkpad> <20210201121322.GC108653@thinkpad> <20210202042208.GB840@work> <20210202201008.274209f9@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <835B2E08-7B84-4A02-B82F-445467D69083@linaro.org> <20210203100508.1082f73e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20210203100508.1082f73e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: Loic Poulain Date: Wed, 3 Feb 2021 19:28:28 +0100 Message-ID: Subject: Re: [RESEND PATCH v18 0/3] userspace MHI client interface driver To: Jakub Kicinski Cc: Manivannan Sadhasivam , Greg KH , David Miller , linux-arm-msm , open list , Jeffrey Hugo , Bhaumik Bhatt , Network Development Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi Jakub, On Wed, 3 Feb 2021 at 19:05, Jakub Kicinski wrote: > > On Wed, 03 Feb 2021 09:45:06 +0530 Manivannan Sadhasivam wrote: > > >> Jakub, Dave, Adding you both to get your reviews on this series. I've > > >> provided an explanation above and in the previous iteration [1]. > > > > > >Let's be clear what the review would be for. Yet another QMI chardev > > >or the "UCI" direct generic user space to firmware pipe? > > > > The current patchset only supports QMI channel so I'd request you to > > review the chardev node created for it. The QMI chardev node created > > will be unique for the MHI bus and the number of nodes depends on the > > MHI controllers in the system (typically 1 but not limited). > > If you want to add a MHI QMI driver, please write a QMI-only driver. > This generic "userspace client interface" driver is a no go. Nobody will > have the time and attention to police what you throw in there later. Think it should be seen as filtered userspace access to MHI bus (filtered because not all channels are exposed), again it's not specific to MHI, any bus in Linux offers that (i2c, spi, usb, serial, etc...). It will not be specific to QMI, since we will also need it for MBIM (modem control path), AT commands, and GPS (NMEA frames), all these protocols are usually handled by userspace tools and not linked to any internal Linux framework, so it would be better not having a dedicated chardev for each of them. Regards, Loic