Linux-Watchdog Archive on
 help / color / Atom feed
From: Mika Westerberg <>
To: Jean Delvare <>
Cc: "Rafael J. Wysocki" <>,
	Len Brown <>,,
	Wim Van Sebroeck <>,
	Guenter Roeck <>,, Tom Abraham <>
Subject: Re: Forcing non-ACPI watchdog driver
Date: Wed, 5 Feb 2020 17:24:35 +0200
Message-ID: <> (raw)
In-Reply-To: <>

On Wed, Feb 05, 2020 at 04:05:29PM +0100, Jean Delvare wrote:
> Hi all,


> Is there a way to prevent the ACPI WDAT watchdog interface from being
> used and force the use of a native watchdog driver instead?
> I have a customer who reports a regression on kernel upgrade. Old
> kernel (v4.4) uses iTCO_wdt and watchdog works, new kernel (v4.12) uses
> wdat_wdt and watchdog doesn't work (instant reboot when opening the
> device). While I'm going to look for fixes to backport, I think it
> would be pretty convenient to have a way to just revert to the working
> driver until the new driver is fixed somehow. But I can't see any way
> to do that at the moment, short of disabling ACPI completely, which is
> definitely too extreme to be considered.
> Am I missing something?

You should be able to revert to iTCO_wdt by simply disabling
CONFIG_WDAT_WDT from .config. Then acpi_has_watchdog() returns false
which means that iTCO_wdt is used instead.

  reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-05 15:05 Jean Delvare
2020-02-05 15:24 ` Mika Westerberg [this message]
2020-02-05 16:30   ` Guenter Roeck
2020-02-05 16:38     ` Mika Westerberg
2020-02-06 14:45       ` Jean Delvare
2020-02-06 14:56         ` Mika Westerberg
2020-02-06 15:50           ` Rafael J. Wysocki
2020-02-06 16:00             ` Rafael J. Wysocki
2020-02-06 19:14               ` Mika Westerberg

Reply instructions:

You may reply publicly 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 \ \ \ \ \ \ \ \ \ \ \

* 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