Linux-Watchdog Archive on lore.kernel.org
 help / Atom feed
From: Guenter Roeck <linux@roeck-us.net>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>,
	linux-watchdog@vger.kernel.org, kernel@pengutronix.de
Subject: Re: What to set in struct watchdog_device::bootstatus?
Date: Thu, 9 May 2019 20:53:42 -0700
Message-ID: <641788d4-7bbf-ed34-6bcb-6f34e1aa261f@roeck-us.net> (raw)
In-Reply-To: <20190509192510.m6o7d63u7e4fs22h@pengutronix.de>

On 5/9/19 12:25 PM, Uwe Kleine-König wrote:
> Hello Guenter,
> 
> On Wed, Feb 20, 2019 at 09:14:08PM +0100, Uwe Kleine-König wrote:
>> In a custom kernel patch stack I found a patch that uses (apart from
>> WDIOF_CARDRESET also) WDIOF_POWERUNDER and WDIOF_EXTERN1 to
>> differentiate the different reset causes. Now that you told using this
>> is wrong, I wonder how these are supposed to be used instead; and there
>> are a few more that according to
>> Documentation/watchdog/watchdog-kernel-api.txt might be used to set
>> bootstatus. Are these a relic? What do these signal?
> 
> I'm still interested in an answer here. While it is currently not
> possible to "fix" the custom kernel as some other software that is
> already shipping depends on this. Still I'd like to know the details
> here to maybe suggest an alternative for the longterm future.
> 
>> IMHO there is a patch opportunity waiting to improve the documenation
>> :-) Or maybe even change watchdog_get_status() to ensure that only
>> WDIOF_CARDRESET, WDIOF_MAGICCLOSE and WDIOF_KEEPALIVEPING can be set?
> 

The basic problem, as I see it, is that the bits were defined a long time
ago as standard API, even tough they really only apply to a small subset
of watchdog cards. Personally I tend to believe that any set of bits
would be insufficient. Maybe it should have been a string. Either case,
I don't believe in forcing more or less random reboot reasons into a
given set of bits. On the other side I also don't see the point in
arbitrarily limiting the bit values returned by WDIOC_GETSTATUS.
With that, my general approach would be some kind of report-what-makes-sense
approach. But using WDIOF_POWERUNDER for "power cycle" just goes a bit too
far.

Thanks,
Guenter

      reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-08 10:52 Uwe Kleine-König
2019-02-08 14:05 ` Guenter Roeck
2019-02-20 20:14   ` Uwe Kleine-König
2019-05-09 19:25     ` Uwe Kleine-König
2019-05-10  3:53       ` Guenter Roeck [this message]

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=641788d4-7bbf-ed34-6bcb-6f34e1aa261f@roeck-us.net \
    --to=linux@roeck-us.net \
    --cc=kernel@pengutronix.de \
    --cc=linux-watchdog@vger.kernel.org \
    --cc=u.kleine-koenig@pengutronix.de \
    --cc=wim@linux-watchdog.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

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

Linux-Watchdog Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-watchdog/0 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/ https://lore.kernel.org/linux-watchdog \
		linux-watchdog@vger.kernel.org linux-watchdog@archiver.kernel.org
	public-inbox-index linux-watchdog


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-watchdog


AGPL code for this site: git clone https://public-inbox.org/ public-inbox