From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:40483 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751538AbcDDRwi (ORCPT ); Mon, 4 Apr 2016 13:52:38 -0400 Date: Mon, 4 Apr 2016 10:52:39 -0700 From: Guenter Roeck To: Geert Uytterhoeven Cc: Wolfram Sang , Linux Watchdog Mailing List , linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH v2 0/4] watchdog: add driver for Renesas Gen3 WDT watchdogs Message-ID: <20160404175239.GA24667@roeck-us.net> References: <1459511786-4286-1-git-send-email-wsa@the-dreams.de> <20160404145919.GE2983@katana> <20160404152506.GA19188@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org On Mon, Apr 04, 2016 at 07:02:45PM +0200, Geert Uytterhoeven wrote: > Hi Günter, > > On Mon, Apr 4, 2016 at 5:25 PM, Guenter Roeck wrote: > > On Mon, Apr 04, 2016 at 05:21:44PM +0200, Geert Uytterhoeven wrote: > >> On Mon, Apr 4, 2016 at 4:59 PM, Wolfram Sang wrote: > >> >> My Salvator-X reboots after timeout from "cat > /dev/watchdog0", but > >> >> it doesn't reboot through "reboot" or "reboot -f"? > >> > > >> > That sadly doesn't work on Gen3. From the RFC v5 cover letter: > >> > >> > === > >> > > >> > * drop restart_handler since ARM64 uses PSCI firmware resets which do > >> > not call restart handlers > >> > > >> > The last point was quite a bummer to me because plain reboot was the > >> > reason I wrote this driver ;) Well, so is life... > >> > >> That's indeed silly. Can't we have it as a low-priority restart handler, to > > > > Yes, it is. It defeats the purpose of restart handlers. PSCI reset should have > > been implemented as a high priority restart handler. > > Unfortunately that won't work: psci_sys_reset() doesn't return on failure. > You mean it just hangs ? That is bad. If that is the case, it is not reliable and thus should be a low priority (or at best medium priority) restart handler (which can be replaced with a working higher priority one). > We can still clear arm_pm_restart in platform code, though ;-) > I had originally planned to replace arm_pm_restart() completely with restart handlers. Maybe I should revive the effort ? Guenter