From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49602C4361B for ; Thu, 17 Dec 2020 16:52:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15EAD208BA for ; Thu, 17 Dec 2020 16:52:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728161AbgLQQwD (ORCPT ); Thu, 17 Dec 2020 11:52:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:53714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727253AbgLQQwB (ORCPT ); Thu, 17 Dec 2020 11:52:01 -0500 X-Gm-Message-State: AOAM5304DHwpgdskwgv1Fy4ikdK/jpMdUI7F6fdAtJPVxrRMIEIpq7e6 VCC2VFPsUyvX/wIPAd9LifS5+CXvUnNpRElxHw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608223880; bh=P5m3N09g7UEzzx6CDYAyM0fEzFb1mPowgoyMkOKqZKA=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=G8RLUc9w2UVQetcvSaxphIRhXVVnrAQqFD9f92OuLOeVEoH4e7y0HxUC2X5TKgQ/z S0gy3uALB+JuCNHh99PMJt/rJCjpZPBIY06G/FfPjT0r04TRb+ri56pBkcuwTfOXG/ byL+uAwmw/5izHvJquFUhEAKNa3DD7G3cOhnvid7wD7Idy3ScddUsX49rh67+2d1n/ du72k78TeAByUQBvzEoiEm2wjqdluYpssbJb9ZPLGW9iZPepOC+r0RNce2AFH+2hcD I07SlzSLdlhDfApVSYaq5p2ttj8c0Na6USnBZ2MfNIEAht4exowyesWpOXCceiW/nW IPGU48CAXukKA== X-Google-Smtp-Source: ABdhPJyBzkrZgMWMBcvlcnLo3tCgsXg3Xa1J3OEC4I62tFNfvgTBx9zRDZ9KJ3sxjoUoRLKwyU4RbkSynkCO9SPDknk= X-Received: by 2002:ad4:4a72:: with SMTP id cn18mr29845197qvb.50.1608223879583; Thu, 17 Dec 2020 08:51:19 -0800 (PST) MIME-Version: 1.0 References: <20201204092752.GE74177@piout.net> <20201211215611.24392-1-rasmus.villemoes@prevas.dk> <20201211215611.24392-2-rasmus.villemoes@prevas.dk> In-Reply-To: From: Rob Herring Date: Thu, 17 Dec 2020 10:51:08 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 1/3] dt-bindings: rtc: add reset-source property To: Rasmus Villemoes Cc: "open list:REAL TIME CLOCK (RTC) SUBSYSTEM" , Alexandre Belloni , "linux-kernel@vger.kernel.org" , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Qiang Zhao , Bruno Thomsen Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 11, 2020 at 5:10 PM Rasmus Villemoes wrote: > > On 11/12/2020 23.30, Rob Herring wrote: > > On Fri, Dec 11, 2020 at 3:56 PM Rasmus Villemoes > > wrote: > >> > >> Some RTCs, e.g. the pcf2127, can be used as a hardware watchdog. But > >> if the reset pin is not actually wired up, the driver exposes a > >> watchdog device that doesn't actually work. > >> > >> Provide a standard binding that can be used to indicate that a given > >> RTC can perform a reset of the machine, similar to wakeup-source. > > > > Why not use the watchdog 'timeout-sec' property? > > Wouldn't that be overloading that property? AFAIU, that is used to ask > the kernel to program an initial timeout value into the watchdog device. > But what if one doesn't want to start the watchdog device at kernel > boot, but just indicate that the RTC has that capability? Yeah, I guess you're right. > It's quite possible that if it can act as a watchdog device (and > has-watchdog was also suggested), one would also want timeout-sec and > other watchdog bindings to apply. But that can be added later, by those > who actually want that. > > For now, I'd really like to get my board booting again (or rather, not > get reset by the real watchdog just because the pcf2127 driver now > exposes something as /dev/wathdog0, pushing the real one to > /dev/wathcdog1 which doesn't get pinged from userspace). I'm wondering how you solve which wdog to ping when there are multiple without relying on numbering. I guess 'reset-source' will solve that even if that's not your current fix. So I guess I'm fine with this. But you need to send to the DT list so checks are run. Rob