Linux-Watchdog Archive on
 help / color / Atom feed
From: Muni Sekhar <>
To: Guenter Roeck <>
Subject: Re: watchdog: how to enable?
Date: Sun, 17 Nov 2019 00:04:47 +0530
Message-ID: <> (raw)
In-Reply-To: <>

On Sat, Nov 16, 2019 at 9:31 PM Guenter Roeck <> wrote:
> 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.

I’m having two same configuration systems, in one system I installed
the Vanilla kernel and I see the /dev/watchdog and /dev/watchdog0
nodes. In other system I’m running with ubuntu distribution kernel,
but I don’t see any watchdog device node. So it looks like I need to
manually load the kernel module in distro kernel. Is there a way to
know what is the corresponding kernel module for  /dev/watchdog node?

# ls -l /dev/watchdog*
crw------- 1 root root  10, 130 Nov 15 17:15 /dev/watchdog
crw------- 1 root root 248,   0 Nov 15 17:15 /dev/watchdog0

# ps -ax | grep watchdog
  678 ?        S      0:00 [watchdogd]

Regarding Super-IO chip, how to find out the Super-IO chip model?

> 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.
How do I use the hardware watchdog to reset my system when system is
frozen? It helps me to collect the crashdump and finally helps me to
find the root cause for the system frozen issue.

> Guenter


  reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-16  0:35 Muni Sekhar
2019-11-16  1:04 ` Guenter Roeck
2019-11-16  3:03   ` Muni Sekhar
2019-11-16 16:01     ` Guenter Roeck
2019-11-16 18:34       ` Muni Sekhar [this message]
2019-11-16 21:42         ` Guenter Roeck
2019-11-18  9:52           ` Muni Sekhar
2019-11-18 14:10             ` Guenter Roeck
2019-11-18 15:07               ` Muni Sekhar
2019-11-18 14:38 ` Bjorn Helgaas
2019-11-18 14:41   ` Bjorn Helgaas
2019-11-18 15:09   ` Muni Sekhar
2019-11-22 10:59     ` Guenter Roeck
2019-11-22 12:54       ` Muni Sekhar

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='' \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Watchdog Archive on

Archives are clonable:
	git clone --mirror linux-watchdog/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-watchdog linux-watchdog/ \
	public-inbox-index linux-watchdog

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone