Re: watchdog: how to enable?

From: Guenter Roeck <linux@roeck-us.net>
To: Muni Sekhar <munisekharrms@gmail.com>
Cc: linux-watchdog@vger.kernel.org, linux-pci@vger.kernel.org,
	wim@linux-watchdog.org
Subject: Re: watchdog: how to enable?
Date: Sat, 16 Nov 2019 08:01:35 -0800	[thread overview]
Message-ID: <e5b24949-5215-9d3d-ca45-cab221d4f58a@roeck-us.net> (raw)
In-Reply-To: <CAHhAz+iSXZSY012-jNx_wmNmgx_UiHZ4rjxkCUcHk3CjLc9gDg@mail.gmail.com>

On 11/15/19 7:03 PM, Muni Sekhar wrote:
[ ... ]
>>
>> Another possibility, of course, might be to enable a hardware watchdog
>> in your system (assuming it supports one). I personally would not trust
>> the NMI watchdog because to detect a system hang, after all, there are
>> situations where even NMIs no longer work.
> 
>>From dmesg , Is it possible to know whether my system supports
> hardware watchdog or not?
> I assume that my system supports the hardware watchdog , then how to
> enable the hardware watchdog to debug the system freeze issues?
> 

Hardware watchdog support really depends on the board type. Most PC
mainboards support a watchdog in the Super-IO chip, but on some it is
not wired correctly. On embedded boards it is often built into the SoC.
The easiest way to see if you have a watchdog would be to check for the
existence of /dev/watchdog. However, on a PC that would most likely
not be there because the necessary module is not auto-loaded.
If you tell us your board type, or better the Super-IO chip on the board,
we might be able to help.

Note though that this won't help to debug the problem. A hardware
watchdog resets the system. It helps to recover, but it is not intended
to help with debugging.

Guenter