From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH 1/3] watchdog: qcom: add support for KPSS WDT Date: Fri, 19 Sep 2014 09:56:31 -0700 Message-ID: <20140919165631.GA32457@roeck-us.net> References: <32d17907ad1dfdcafe4e76f33adc2ff22631cd28.1411078425.git.joshc@codeaurora.org> <541B97CD.60400@roeck-us.net> <20140919032416.GE3749@joshc.qualcomm.com> <541BA5F7.1030704@roeck-us.net> <20140919162550.GI3749@joshc.qualcomm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140919162550.GI3749@joshc.qualcomm.com> Sender: linux-kernel-owner@vger.kernel.org To: Josh Cartwright Cc: Wim Van Sebroeck , Grant Likely , Rob Herring , devicetree@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Kumar Gala , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Fri, Sep 19, 2014 at 11:25:50AM -0500, Josh Cartwright wrote: > On Thu, Sep 18, 2014 at 08:41:43PM -0700, Guenter Roeck wrote: > > On 09/18/2014 08:24 PM, Josh Cartwright wrote: > > >On Thu, Sep 18, 2014 at 07:41:17PM -0700, Guenter Roeck wrote: > > >>On 09/18/2014 03:26 PM, Josh Cartwright wrote: > > >>>Add a driver for the watchdog timer block found in the Krait Processor > > >>>Subsystem (KPSS) on the MSM8960, APQ8064, and IPQ8064. > > >>> > > >>>Signed-off-by: Josh Cartwright > > >> > > >>Hi Josh, > > >> > > >>comments inline. > > > > > >Thanks for taking a look! > > > > [..] > > >>>+ watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev); > > >> > > >>That leaves you with no default timeout if timeout-sec is not set in devicetree, > > >>which if I understand the code correctly might result in an immediate reset. > > >>Is this really what you want to happen ? > > > > > >I think I'd like to handle timeout-sec being unspecified as an error at > > >probe. If someone explicitly sets timeout-sec = <0>, then they get what > > >they ask for. I'll take another look to see how to make this happen. > > > > > > > Hmm.. kind of unusual. Usual would be to initialize the timeout together > > with min_timeout / max_timeout above and only force the user to specify > > a value if the default timeout is not desirable. You don't really gain > > anything by making timeout-sec mandatory. > > Making timeout-sec mandatory makes it so I don't have to decide what a > "sane default" is. :) > Bad excuse ;-). You just force others to make the decision for you. > It's even less clear about what a sane default is looking at the other > watchdog drivers. From the drivers I looked at, it ranges any where > from 30s to 2mins. Am I just to choose? Why do these even differ > between all of the drivers? > Sanity is defined as the majority opinion, as expressed quite nicely in "Everyone is insane but me". Just pick something in between. If you don't want to make a decision, pick 30 seconds and blame it on me. Maybe someone at some point finds a common ground. Until then it is per driver. Thanks, Guenter