Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1432404AbdDYQ6l (ORCPT ); Tue, 25 Apr 2017 12:58:41 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:49865 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1432352AbdDYQ6c (ORCPT ); Tue, 25 Apr 2017 12:58:32 -0400 Date: Tue, 25 Apr 2017 09:58:24 -0700 From: Guenter Roeck To: Alexandre Belloni Cc: Moritz Fischer , Linux Kernel Mailing List , Moritz Fischer , linux-watchdog@vger.kernel.org, wim@iguana.be, a.zummo@towertech.it, rtc-linux@googlegroups.com, alex.williams@ni.com Subject: Re: [PATCH 0/2] DS1374 Watchdog fixes Message-ID: <20170425165824.GA10024@roeck-us.net> References: <1493071512-5718-1-git-send-email-mdf@kernel.org> <5f8fac22-4037-9983-436a-da8ff87d4b17@roeck-us.net> <20170425161743.GA8443@roeck-us.net> <20170425163204.rj6on6phtbfuvcd7@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170425163204.rj6on6phtbfuvcd7@piout.net> User-Agent: Mutt/1.5.24 (2015-08-30) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2800 Lines: 63 On Tue, Apr 25, 2017 at 06:32:04PM +0200, Alexandre Belloni wrote: > On 25/04/2017 at 09:17:43 -0700, Guenter Roeck wrote: > > On Tue, Apr 25, 2017 at 07:55:28AM -0700, Moritz Fischer wrote: > > > Hi Guenter, > > > > > > On Mon, Apr 24, 2017 at 10:03 PM, Guenter Roeck wrote: > > > > On 04/24/2017 03:05 PM, Moritz Fischer wrote: > > > > > > >> I'm very unhappy with the CONFIG_DRV_RTC_DS1374_WDT way of enabling > > > >> the watchdog behavior and currently I'm investigating how to make > > > >> that work via DT. > > > >> > > > >> Watchdog maintainers, do you have an idea on how to do that in a > > > >> non breaking fashion? > > > >> > > > > > > > > Depends on what you mean with "non breaking". Just using the normal mfd > > > > mechanisms, ie define an mfd cell for each client driver, should work. > > > > Do you see any problems with that ? Either case, that doesn't seem > > > > to be a watchdog driver problem, or am I missing something ? > > > > > > Well so currently watchdog behavior is selected (out of the two options alarm, > > > or watchdog) by enabling the configuration option mentioned above. > > > If I change this over to use a dt-based approach like dallas,ds1374-mode = <2>; > > > to select the behavior in the mfd for example, won't that break people that > > > relied on the old behavior? If everyone involved is ok with that, I'm happy > > > to just add it to the binding. > > > > > > > Sorry, I must be missing something. Looking into the driver code, my > > understanding is that CONFIG_RTC_DRV_DS1374_WDT enables the watchdog in > > addition to rtc functionality, not one or the other. Sure you would need > > a different configuration option if you were to move the watchdog code into > > drivers/watchdog, but other than that I don't really understand the problem. > > What is the issue with, for example, > > > > The watchdog functionality and the rtc alarm are mutually exclusive. > Ah, I missed the "n" in various #ifndef statements. I can't really comment on how to solve that; I simply don't know. Also, even with a dt property, it still would be necessary to have a non-DT means to configure one or the other. Making whatever solution backward compatible also seems tricky; I don't have a solution for that problem either. > > > The idea was to fix what's broken currently (this patchset) and then refactor. > > > But if you prefer I can do all in one go instead. > > > > > > > It just seemed a waste to me to change/fix a function which is going to > > be removed in a subsequent patch (I seem to recall that there was a fix > > to the ioctl function). > > > > I'd say that it depends on whether you want to backport the fixes to the > stable kernels. Backporting the full rework is probably riskier. > Good point. Guenter