Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device on event

From	One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Newsgroups	linux.kernel
Subject	Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device on event
Date	2015-12-18 18:30 +0100
Message-ID	<qH70S-8A-3@gated-at.bofh.it> (permalink)
References	<qGIca-Ma-7@gated-at.bofh.it> <qGIca-Ma-25@gated-at.bofh.it> <qH6Hw-8tp-17@gated-at.bofh.it>
Organization	Intel Corporation

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> I am not really happy about the watchdog device appearing and disappearing
> dynamically. This wreaks havoc with any standard watchdog application.

Any software that doesn't handle this has been broken for over fifteen
years. We have hotplug PCI and we have PCI watchdog card support. This
isn't a new behaviour to anyone outside the embedded single board space.

> Isn't there a better way to handle this ? How about just registering the
> watchdog device and return an error in the access functions if it is disabled ?

That breaks the existing behaviour of hot pluggable watchdog interfaces
and is different to just about any other device in the kernel. Today with
any desktop or server distribution you can already trivially arrange for
watchdog daemons to start at the point a watchdog is detected dynamically.

Alan
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Thread

[char-misc-next v2 0/7] mei: create proper iAMT watchdog driver Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
  [char-misc-next v2 2/7] mei: wd: drop the watchdog code from the core mei driver Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
  [char-misc-next v2 1/7] mei: drop nfc leftovers from the mei driver Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
  [char-misc-next v2 6/7] watchdog: mei_wdt: register wd device only if required Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
    Re: [char-misc-next v2 6/7] watchdog: mei_wdt: register wd device  only if required Guenter Roeck <linux@roeck-us.net> - 2015-12-18 18:00 +0100
      RE: [char-misc-next v2 6/7] watchdog: mei_wdt: register wd device  only if required "Winkler, Tomas" <tomas.winkler@intel.com> - 2015-12-20 13:30 +0100
        Re: [char-misc-next v2 6/7] watchdog: mei_wdt: register wd device  only if required Guenter Roeck <linux@roeck-us.net> - 2015-12-20 19:20 +0100
  [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device on event Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
    Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device on  event Guenter Roeck <linux@roeck-us.net> - 2015-12-18 18:10 +0100
      Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device  on event One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2015-12-18 18:30 +0100
        Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device on  event Guenter Roeck <linux@roeck-us.net> - 2015-12-18 19:00 +0100
          Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device  on event One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2015-12-18 19:20 +0100
            RE: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device  on event "Winkler, Tomas" <tomas.winkler@intel.com> - 2015-12-20 14:00 +0100
  [char-misc-next v2 5/7] mei: bus: whitelist the watchdog client Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
  [char-misc-next v2 3/7] watchdog: mei_wdt: implement MEI iAMT watchdog driver Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
    Re: [char-misc-next v2 3/7] watchdog: mei_wdt: implement MEI iAMT  watchdog driver Guenter Roeck <linux@roeck-us.net> - 2015-12-18 17:40 +0100
  [char-misc-next 4/7] watchdog: mei_wdt: add status debugfs entry Tomas Winkler <tomas.winkler@intel.com> - 2015-12-17 16:00 +0100
    Re: [char-misc-next 4/7] watchdog: mei_wdt: add status debugfs entry Guenter Roeck <linux@roeck-us.net> - 2015-12-18 17:50 +0100
      RE: [char-misc-next 4/7] watchdog: mei_wdt: add status debugfs entry "Winkler, Tomas" <tomas.winkler@intel.com> - 2015-12-20 10:50 +0100
        Re: [char-misc-next 4/7] watchdog: mei_wdt: add status debugfs entry Guenter Roeck <linux@roeck-us.net> - 2015-12-20 11:50 +0100
          RE: [char-misc-next 4/7] watchdog: mei_wdt: add status debugfs entry "Winkler, Tomas" <tomas.winkler@intel.com> - 2015-12-20 13:00 +0100

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