From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Valentin Subject: Re: [PATCH 1/7] dt-bindings: Add DT bindings documentation for Allwinner Thermal Sensor Controller Date: Fri, 24 Aug 2018 16:03:40 -0700 Message-ID: <20180824230338.GA19399@localhost.localdomain> References: <20180804070355.14857-1-manu@freebsd.org> <20180820111755.rzg7l2lznmbpuf2e@flea> <20180820140737.xmqhu5ndqzehvkql@flea> <20180820162715.49e6d8a469ece983f3c1d288@bidouilliste.com> <20180824145840.isdcg3fr6mw4ntzg@flea> <20180824215921.59d060b54eb3a1e7d1552bde@bidouilliste.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20180824215921.59d060b54eb3a1e7d1552bde@bidouilliste.com> Sender: linux-kernel-owner@vger.kernel.org To: Emmanuel Vadot Cc: Maxime Ripard , Rob Herring , Mark Rutland , "open list:THERMAL" , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , Emmanuel Vadot , Chen-Yu Tsai , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , Zhang Rui , devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On Fri, Aug 24, 2018 at 09:59:21PM +0200, Emmanuel Vadot wrote: >=20 > Hi, >=20 > On Fri, 24 Aug 2018 16:58:40 +0200 > Maxime Ripard wrote: >=20 > > Hi, > >=20 > > On Mon, Aug 20, 2018 at 04:27:15PM +0200, Emmanuel Vadot wrote: > > > On Mon, 20 Aug 2018 16:07:37 +0200 > > > Maxime Ripard wrote: > > >=20 > > > > On Mon, Aug 20, 2018 at 07:41:22AM -0600, Rob Herring wrote: > > > > > On Mon, Aug 20, 2018 at 5:17 AM Maxime Ripard wrote: > > > > > > > > > > > > On Sat, Aug 04, 2018 at 09:03:49AM +0200, Emmanuel Vadot wrote: > > > > > > > This patch adds documentation for Device-Tree bindings for th= e Allwinner > > > > > > > Thermal Sensor Controller found on the H3, H5 and A64 SoCs > > > > > > > > > > > > > > Signed-off-by: Emmanuel Vadot > > > > > > > > > > > > I'm not going to merge a binding for a device that doesn't have= any > > > > > > driver implemented at the moment in Linux. > > > > >=20 > > > > > I'll take it then. Linux is not the only DT client. > > > >=20 > > > > Then don't complain if we ever have to break the ABI. We never test= ed > > > > that hardware, never had any code running on it, and it *will* cause > > > > some issues. For example, the calibration data have never been used > > > > and how they should be represented have never been described, since= no > > > > one ever actually tried to use it. > > > >=20 > > > > And sure, Linux is not the only DT client. Just like FreeBSD isn't. > > >=20 > > > What kind of data would you need for me to make things better ? > > > We have the driver in FreeBSD for almost two years now, whne I start= ed > > > to see how to upstream it I noticed a lot of problems and spent 4 or 5 > > > days to try on all the SoCs mentionned in the serie, the only SoC I > > > didn't include it the A83T as for some reason I couldn't make the > > > driver work. > >=20 > > Do you have a link to that driver?=20 >=20 > https://github.com/freebsd/freebsd/blob/master/sys/arm/allwinner/aw_ther= mal.c >=20 > > How and how much did you test it? >=20 > Using a cheap IR thermometer as it's all I can afford. > Then running multiples cpufreq-a53 process and comparing the result. > Did the same without using the calibration data, result where closer > when I used them. >=20 > > Are you using the calibration data stored in the SID? >=20 > Yes, which is why the serie contain the nvmem cell for the SID. >=20 > >=20 > > > I just hope that you understand that we cannot wait for Linux to > > > have a driver to have some bindings. > >=20 > > Just like I'm sure you can understand that just merging the DT bits > > without testing anything caused some troubles in the past, and I don't > > want to discover it in a year from now. >=20 > I do, I don't like wrong DT info as much as you do I think. I had > the unfortunate event to find that the sun4i-a10-timer compatible used > in every soc is plain wrong for !A10 and !A13, patches comming soon. > I want those bits merged but I also want that they reflect reality, > this is not a hard driver to do, NetBSD also have one I think, maybe > OpenBSD do to. I would prefer to see a series of DT bindings + driver. Can you send your next iteration with the driver so we can review both together? >=20 > > Maxime > >=20 > > --=20 > > Maxime Ripard, Bootlin > > Embedded Linux and Kernel engineering > > https://bootlin.com >=20 >=20 > --=20 > Emmanuel Vadot