From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1521467660; cv=none; d=google.com; s=arc-20160816; b=REUCUL19b7RXAIdtVVOFxgZ0j9KRLW4pyMUpIMkI5VkiYLlAIBxLQkT9nWm2YHOgdn jXAGKjHTX8R51W40l+fpw0yytSxjZzyLZSkz0AxSjFDKuX3kKFMQJjmuvzLYCEy+ucuP c8KOh70l5WjrwQ5TDdmlEsTMsyXj9BxO6AM5IZuCfbg1MzoW82/ghj2YdeXvsRjai7ca +IKTZ6hUBnXkq32KWwsisRd2qhZXwb3mNtH1o2SQP5oeYy1YA9eY9MuF4BEO/Cr57liK 87/+pBCCjdzzXszODT3sPhirrmS4ABNmXXGis6/ecybPZ6F9i4UAJla93AjL8jqGFbxZ quyA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:sender:dkim-signature :arc-authentication-results; bh=a7IOpzZw6/7yEyXRAOTavwL8UN9+uNF0HfI5H3QZQgs=; b=zO78eM2/5mXdW6T2GWfsoxpuXs9atcx3GIHhG6ZAZSnUU8Aff0+l0qXwwbA0ToP8Pv NYEs9iHwNHXzw+r5/mmlu80xbth+e10bvgxpCTwbAKssVHflBRp8Cwb/aJNLoR0maXHv bKpMUxQseDsosRiUktc+gqJ9UGgaMC5RBkz4SIJBxqrJEYXmti1oHWI/YA0JV4QEQgqM HMzs8HmmwDRoyYUTTIiHVyErBJDIcS8ShwlkWdYqIE14HssBeUWJ6JbMB/+NebwvUICy Gbc8A9WbxDNws/Gyg/7R2SyWukXsuBM0XeUT8uQHG2Z9vI5caooU7S1l8dHYR7O2qzaH ndHQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Xxv4svnO; spf=pass (google.com: domain of jhovold@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=jhovold@gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Xxv4svnO; spf=pass (google.com: domain of jhovold@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=jhovold@gmail.com X-Google-Smtp-Source: AG47ELtptmgm4AHY6BpOjDUojTh2ytsImEwPfnlGxHlxxq31/fq/3hxSzyCDKGiE17qu7CMY+lTVQA== Sender: Johan Hovold Date: Mon, 19 Mar 2018 14:54:18 +0100 From: Johan Hovold To: "H. Nikolaus Schaller" Cc: Johan Hovold , Mark Rutland , DTML , Discussions about the Letux Kernel , =?iso-8859-1?Q?Beno=EEt?= Cousson , Arnd Bergmann , Tony Lindgren , Greg Kroah-Hartman , kernel@pyra-handheld.com, Russell King , Linux Kernel Mailing List , linux-omap , Rob Herring , Linux ARM , Pavel Machek , Kevin Hilman , Thierry Reding , Andreas =?iso-8859-1?Q?F=E4rber?= , Jonathan Cameron Subject: Re: [Letux-kernel] [PATCH v5 3/5] misc serdev: Add w2sg0004 (gps receiver) power control driver Message-ID: <20180319135418.GL18359@localhost> References: <5494ad34b39a6c62601e3747440268dfb3be7d5a.1512114576.git.hns@goldelico.com> <20171222124427.GI3374@localhost> <91850CC3-B280-4701-9D07-96AFF3A79A6F@goldelico.com> <90F9A8E4-035A-4A9E-8AAB-757491D63E69@goldelico.com> <20180112153903.GB5992@localhost> <20180212152618.GC13962@amd> <20180227070415.GB18666@localhost> <22A8F5FE-C8B9-46EB-B98D-A94EA4170131@goldelico.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <22A8F5FE-C8B9-46EB-B98D-A94EA4170131@goldelico.com> User-Agent: Mutt/1.7.2 (2016-11-26) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1584169666984958099?= X-GMAIL-MSGID: =?utf-8?q?1595374473677219424?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, Feb 27, 2018 at 08:32:50AM +0100, H. Nikolaus Schaller wrote: > Hi Johan, > > > Am 27.02.2018 um 08:04 schrieb Johan Hovold : > > > > On Mon, Feb 12, 2018 at 04:26:18PM +0100, Pavel Machek wrote: > >> Hi! > >> > >>>> Let's restart this discussion and focus on the main roadblock (others > >>>> are minor details which can be sorted out later). > >>>> > >>>> If it feels like a hack, the key issue seems to me to be the choice of > >>>> the API to present the GPS data to user space. Right? > >>> > >>> Or even more fundamentally, does this belong in the kernel at all? > >> > >> Yes, it does. > > Thanks, Pavel for supporting our view. > > > > > But not necessarily in its current form. > > Is this a "yes after some code fixes"? No, we need some kind of at least rudimentary gps framework even if we allow for a raw (NMEA) interface for the time being (possibly indefinitely). > Pavel mentioned an example where such an evolutionary approach was taken. > > > >>> Now, if we'd ever have a proper GPS framework that handled everything in > >>> kernel space (i.e. no more gpsd) then we would be able to write kernel > >>> drivers that also take care of PM. But perhaps that's unlikely to ever > >>> be realised given the state of things (proprietary protocols, numerous > >>> quirky implementations, etc). > >> > >> That is what needs to happen. > >> > >>> The kernel is probably not the place to be working around issues like > >>> that, even if serdev at least allows for such hacks to be fairly > >>> isolated in drivers (unlike some of the earlier proposals touching core > >>> code). > >> > >> Oh, kernel is indeed right place to provide hardware abstraction -- > >> and that includes bug workarounds. > > > > Right, at least when such hacks can be confined to a driver and not be > > spread all over the place. > > It seems that you forgot that the driver we propose is not spread all over > the place. It *is* confined to a single driver thanks to the serdev api. I believe that's what I wrote above. Johan