From: Guenter Roeck <linux@roeck-us.net>
To: Rostislav Lisovy <lisovy@gmail.com>
Cc: Wim Van Sebroeck <wim@iguana.be>,
linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
sojkam1@fel.cvut.cz, michal.vokac@comap.cz,
Rostislav Lisovy <lisovy@merica.cz>
Subject: Re: [PATCH v2] watchdog: omap_wdt: Add 'early_disable' module parameter
Date: Tue, 23 Sep 2014 09:14:40 -0700 [thread overview]
Message-ID: <20140923161440.GC20591@roeck-us.net> (raw)
In-Reply-To: <1411469087.32524.6.camel@lp-lvrv.comap.cz>
On Tue, Sep 23, 2014 at 12:44:47PM +0200, Rostislav Lisovy wrote:
> On Čt, 2014-09-18 at 21:12 -0700, Guenter Roeck wrote:
> > How about reading the OMAP_WATCHDOG_SPR register ?
>
> Unfortunately this would be not only extremely fragile (someone writes
> correct start sequence followed by some garbage -- WD is running and we
> are reading garbage) but according to some experiments seems not to work
> at all (I am reading "0" even for a running WD probably as a result to
> the pm_runtime_get_sync() call).
>
> One of the TI employees on the TI forum confirmed (I know this is not a
> rock-solid information) that it is not possible to safely determine if
> the WD is running or not.
>
Annoying, but I guess we'll have to live with that.
>
> > Either case, you can not issue a message about the watchdog being
> > stopped or started if you don't know if it was actually stopped
> > or started. Also, if you don't really know if the watchdog was
> > stopped or started, all you can do is to either stop or start it,
> > without judgment about its previous condition.
>
> You are right. I was blinded by our use case where the watchdog is
> always started by the bootloader.
> I will wait to see if the WATCHDOG_KEEP_ON will be integrated and then I
> will add the feature for the omap_wdt.
>
I would predict that it will be accepted. For my part I am not happy
with the name, though, and I'll have to find the time to thoroughly review
and, if possible, test it.
Guenter
prev parent reply other threads:[~2014-09-23 16:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-16 14:20 Rostislav Lisovy
2014-09-16 15:49 ` Guenter Roeck
2014-09-17 15:22 ` Rostislav Lisovy
2014-09-19 4:12 ` Guenter Roeck
2014-09-23 10:44 ` Rostislav Lisovy
2014-09-23 16:14 ` Guenter Roeck [this message]
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:
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=20140923161440.GC20591@roeck-us.net \
--to=linux@roeck-us.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-watchdog@vger.kernel.org \
--cc=lisovy@gmail.com \
--cc=lisovy@merica.cz \
--cc=michal.vokac@comap.cz \
--cc=sojkam1@fel.cvut.cz \
--cc=wim@iguana.be \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome