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[209.132.180.67]) by mx.google.com with ESMTP id e4si802782pgr.627.2018.02.12.08.56.05; Mon, 12 Feb 2018 08:56:21 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753300AbeBLP0X (ORCPT + 99 others); Mon, 12 Feb 2018 10:26:23 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:43091 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbeBLP0V (ORCPT ); Mon, 12 Feb 2018 10:26:21 -0500 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 613E480160; Mon, 12 Feb 2018 16:26:19 +0100 (CET) Date: Mon, 12 Feb 2018 16:26:18 +0100 From: Pavel Machek To: Johan Hovold Cc: "H. Nikolaus Schaller" , Mark Rutland , DTML , Thierry Reding , Jonathan Cameron , Arnd Bergmann , Tony Lindgren , Greg Kroah-Hartman , Russell King , Linux Kernel Mailing List , Rob Herring , Kevin Hilman , =?iso-8859-1?Q?Beno=EEt?= Cousson , kernel@pyra-handheld.com, Discussions about the Letux Kernel , linux-omap , Andreas =?iso-8859-1?Q?F=E4rber?= , Linux ARM Subject: Re: [Letux-kernel] [PATCH v5 3/5] misc serdev: Add w2sg0004 (gps receiver) power control driver Message-ID: <20180212152618.GC13962@amd> 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> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="dkEUBIird37B8yKS" Content-Disposition: inline In-Reply-To: <20180112153903.GB5992@localhost> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --dkEUBIird37B8yKS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > Let's restart this discussion and focus on the main roadblock (others > > are minor details which can be sorted out later). > >=20 > > 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? >=20 > Or even more fundamentally, does this belong in the kernel at all? Yes, it does. > Given that we'd still depend on gpsd and other, proprietary, daemons to > actually parse and use (also for control) the plethora of GPS protocols > available, it may even be best to just keep it all in user space. No. We'd want to move away from gpsd in the long term. (/dev/input/mice was in similar situation.) > 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. We'd like unmodified userspace to run on any supported hardware, remember? Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --dkEUBIird37B8yKS Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlqBshoACgkQMOfwapXb+vLq0ACfa+0cUfIudCx3JKPfpMHeQ9Fk se8AoIjq1ci/aJ0lgBOdyzieOOILfG/Q =amcf -----END PGP SIGNATURE----- --dkEUBIird37B8yKS--