From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Mon, 23 Nov 2015 18:31:37 -0500 From: Damien Riegel To: Harald Geyer , wim@iguana.be, linux-watchdog@vger.kernel.org, Vivien Didelot , linux@roeck-us.net Subject: Re: In-reply-to: <1448056496-2335-1-git-send-email-damien.riegel@savoirfairelinux.com> Message-ID: <20151123233136.GA18839@localhost> References: <1448056496-2335-2-git-send-email-damien.riegel@savoirfairelinux.com> <20151123153747.GA13332@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: List-ID: On Mon, Nov 23, 2015 at 07:20:57PM +0100, Harald Geyer wrote: > Damien Riegel writes: > > > + if (code == SYS_DOWN || code == SYS_HALT) { > > > > > > I think you want this to be (code == SYS_POWER_OFF || code == SYS_HALT) > > > AFAIK SYS_DOWN is the code for a reboot, where the system should come > > > back up immediatly, so probably we shouldn't disable the watchdog in > > > this case, for the system might crash during going down. > > > > Well, most of the drivers (all of them but gpio) that I changed stopped > > on SYS_HALT and SYS_DOWN, so they explicitely wanted to stop the > > watchdog on reboot. I just factorized that in watchdog core. > > If they wanted to do so, or the code just got copied around, is > unclear. SYS_DOWN isn't the most helpful name after all, but ... > > > Maybe they should not stop on reboot in the first place, but this serie > > does not introduce a new behaviour. > > okay. I can always send a follow up patch, if I care enough. > I don't understand why you assume this is not the desired behaviour and that the code was just copied around. > > > More importantly however we should stop the watchdog on SYS_POWER_OFF > > > I think. > > > > > My understanding here is that if the system is powered off, the watchdog > > will be powered off too, so there is no need to stop it. > > This is true for many platforms, but I'm pretty sure that not all > platforms have a real power off. So unless you can think of a reason not > to stop the watchdog on power off, I think the core should do it. > Actually if this can't be the default, we probably need to extend > your code so that drivers can select the behaviour they want. > (Of course we would hate to do that, as power management and watchdogs > are pretty orthogonal subsystems and having one depend on the behaviour > of the other is very unfortunate.) We have to assume that power-off means that the system will be powered off (...). If a platform has no real power-off, then it should be halted, and in that case the core would stop the watchdog to prevent a spurious reboot. But maybe you're right and we should not make such distinction between power-off and halt, but I don't really want to make changes in drivers I don't know the context in which they are used. Damien.