User-Agent: Cyrus-JMAP/3.5.0-alpha0-1371-g2296cc3491-fm-20211109.003-g2296cc34
Mime-Version: 1.0
Message-Id: <95dea968-f452-4ba0-9b66-c9bc4269a52c@www.fastmail.com>
In-Reply-To: <YY/YnlCxLqdw/zAo@sunset>
References: <20211113094732.73889-1-sven@svenpeter.dev>
 <20211113094732.73889-2-sven@svenpeter.dev> <YY/YnlCxLqdw/zAo@sunset>
Date:   Sun, 14 Nov 2021 12:37:42 +0100
From:   "Sven Peter" <sven@svenpeter.dev>
To:     "Alyssa Rosenzweig" <alyssa@rosenzweig.io>
Cc:     "Wim Van Sebroeck" <wim@linux-watchdog.org>,
        "Guenter Roeck" <linux@roeck-us.net>,
        "Hector Martin" <marcan@marcan.st>,
        "Rob Herring" <robh+dt@kernel.org>,
        "Mark Kettenis" <mark.kettenis@xs4all.nl>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-watchdog@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/2] watchdog: Add Apple SoC watchdog driver
Content-Type: text/plain
Precedence: bulk


On Sat, Nov 13, 2021, at 16:24, Alyssa Rosenzweig wrote:
>> + * This HW block has three separate watchdogs. WD0 resets the machine
>> + * to recovery mode and is not very useful for us. WD1 and WD2 trigger a normal
>> + * machine reset. WD0 additionally supports a configurable interrupt.
>
> Do we have any idea what the difference between WD1 and WD2 is?

I've never seen macOS write to WD2 when running in our hypervisor and only
found that one when I was looking at the rest of the MMIO region.
From what I can tell it works exactly like WD1.

Sven