From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from top.free-electrons.com ([176.31.233.9]:52345 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752284AbaB1PJf (ORCPT ); Fri, 28 Feb 2014 10:09:35 -0500 Date: Fri, 28 Feb 2014 12:09:26 -0300 From: Ezequiel Garcia To: Jason Gunthorpe Cc: linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Thomas Petazzoni , Gregory Clement , Lior Amsalem , Tawfik Bayouk , Wim Van Sebroeck Subject: Re: [PATCH 0/2] Watchdog on Armada 375 SoC Message-ID: <20140228150925.GC24805@localhost> References: <1393419047-10071-1-git-send-email-ezequiel.garcia@free-electrons.com> <20140226203633.GA24656@obsidianresearch.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20140226203633.GA24656@obsidianresearch.com> Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org Content-Transfer-Encoding: quoted-printable On Wed, Feb 26, 2014 at 01:36:33PM -0700, Jason Gunthorpe wrote: > On Wed, Feb 26, 2014 at 09:50:45AM -0300, Ezequiel Garcia wrote: > =20 > > Here we found both the above RSTOUT: > >=20 > > 1. It has the same dedicated register as A370/XP (0x20704) > > 2. Also has a bit in the shared RSTOUT register (0x18254) >=20 > Unless you know otherwise I think the same risk exists, RSTOUT could > be (or become) internally asserted when you unmask the bit in the > control register that drives the pin, which says the watchdog driver > should control to it. >=20 I guess it's also possible to have the system-controller ensure the watchdog is fully stopped, before unmasking the shared RSTOUT. However, it seems it would be too ugly and hackish. > >=20 > > watchdog-timer@20300 { > > compatible =3D "marvell,orion-wdt"; > > reg =3D <0x20300 0x28 > > {shared RSOUT} 0x4 > > 0x0 0x0>; > > }; >=20 > I wouldn't have the 0x0, if you want to go this way, just make the > 375 compatible string require a 3 entry reg. >=20 Yes, this sounds like the right thing to do. It means we need to also have per-SoC hooks for stop() and is_enabled(), but it's the price to pay for changing the register semantic: the shared RSTOUT has unmask/mask semantics on A375, while it's enable/disable on Kirkwood and friends. Let me cook a new patch. --=20 Ezequiel Garc=C3=ADa, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html