From: Arnd Bergmann <arnd@arndb.de>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>,
wim@iguana.be, dbaryshkov@gmail.com, dwmw2@infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org,
linux-sunxi@googlegroups.com
Subject: Re: [PATCH v2 1/6] wdt: sunxi: Move restart code to the watchdog driver
Date: Mon, 23 Jun 2014 17:35 +0200 [thread overview]
Message-ID: <4880375.uMKpQASVMt@wuerfel> (raw)
In-Reply-To: <53A844C2.7070804@roeck-us.net>
On Monday 23 June 2014 08:16:18 Guenter Roeck wrote:
> > Moved to where?
> >
> > I certainly don't want it in the platform directories, and for arm64 we
> > intentionally don't have a place to put this stuff.
> >
>
> I have no idea, but setting the arm reset function pointer from a watchdog
> driver doesn't seem like a good idea either. The arm code _does_ provide
> and expect platform code to set the reset function, so having it in the arm
> code would at least make more sense than expecting some unrelated driver
> code to set it - especially since it is inherently racy [1].
I don't think the race is inherent. We could solve the multiple registration
problem and the unload problem using a notifier chain. If there are actually
cases where we expect to see multiple reboot functions to be present in the
system, we could go one step further and have a priority associated with
it, so we try the best function first and fall back to soft_restart()
if everything else fails.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/6] wdt: sunxi: Move restart code to the watchdog driver
Date: Mon, 23 Jun 2014 17:35 +0200 [thread overview]
Message-ID: <4880375.uMKpQASVMt@wuerfel> (raw)
In-Reply-To: <53A844C2.7070804@roeck-us.net>
On Monday 23 June 2014 08:16:18 Guenter Roeck wrote:
> > Moved to where?
> >
> > I certainly don't want it in the platform directories, and for arm64 we
> > intentionally don't have a place to put this stuff.
> >
>
> I have no idea, but setting the arm reset function pointer from a watchdog
> driver doesn't seem like a good idea either. The arm code _does_ provide
> and expect platform code to set the reset function, so having it in the arm
> code would at least make more sense than expecting some unrelated driver
> code to set it - especially since it is inherently racy [1].
I don't think the race is inherent. We could solve the multiple registration
problem and the unload problem using a notifier chain. If there are actually
cases where we expect to see multiple reboot functions to be present in the
system, we could go one step further and have a priority associated with
it, so we try the best function first and fall back to soft_restart()
if everything else fails.
Arnd
next prev parent reply other threads:[~2014-06-23 15:35 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-07 2:44 [PATCH v2 0/6] ARM: sunxi: Machine code cleanup Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
2014-05-07 2:44 ` [PATCH v2 1/6] wdt: sunxi: Move restart code to the watchdog driver Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
2014-05-07 21:33 ` Guenter Roeck
2014-05-07 21:33 ` Guenter Roeck
2014-05-15 9:11 ` Maxime Ripard
2014-05-15 9:11 ` Maxime Ripard
2014-05-19 15:04 ` Maxime Ripard
2014-05-19 15:04 ` Maxime Ripard
2014-05-22 20:34 ` Maxime Ripard
2014-05-22 20:34 ` Maxime Ripard
2014-05-22 20:39 ` One Thousand Gnomes
2014-05-22 20:39 ` One Thousand Gnomes
2014-05-22 20:56 ` Maxime Ripard
2014-05-22 20:56 ` Maxime Ripard
2014-06-23 21:16 ` Wim Van Sebroeck
2014-05-22 21:12 ` Guenter Roeck
2014-05-22 21:12 ` Guenter Roeck
2014-05-23 8:33 ` Maxime Ripard
2014-05-23 8:33 ` Maxime Ripard
2014-06-23 10:31 ` Maxime Ripard
2014-06-23 10:31 ` Maxime Ripard
2014-06-23 14:30 ` Guenter Roeck
2014-06-23 14:30 ` Guenter Roeck
2014-06-23 14:42 ` Arnd Bergmann
2014-06-23 14:42 ` Arnd Bergmann
2014-06-23 15:16 ` Guenter Roeck
2014-06-23 15:16 ` Guenter Roeck
2014-06-23 15:35 ` Arnd Bergmann [this message]
2014-06-23 15:35 ` Arnd Bergmann
2014-06-23 15:40 ` Guenter Roeck
2014-06-23 15:40 ` Guenter Roeck
2014-06-23 15:49 ` Maxime Ripard
2014-06-23 15:49 ` Maxime Ripard
2014-06-23 21:30 ` Wim Van Sebroeck
2014-06-23 21:47 ` Guenter Roeck
2014-06-23 21:47 ` Guenter Roeck
2014-06-24 9:27 ` Arnd Bergmann
2014-06-24 9:27 ` Arnd Bergmann
2014-06-23 21:13 ` Wim Van Sebroeck
2014-06-24 14:49 ` Maxime Ripard
2014-06-24 14:49 ` Maxime Ripard
2014-06-24 16:01 ` Guenter Roeck
2014-06-24 16:01 ` Guenter Roeck
2014-08-02 8:02 ` Wim Van Sebroeck
2014-08-02 15:17 ` Maxime Ripard
2014-08-02 15:17 ` Maxime Ripard
2014-08-02 15:45 ` Guenter Roeck
2014-08-02 15:45 ` Guenter Roeck
2014-05-07 2:44 ` [PATCH v2 2/6] power: reset: Add Allwinner A31 reset code Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
2014-05-07 2:44 ` [PATCH v2 3/6] ARM: sunxi: Remove reset code from the platform Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
2014-05-07 2:44 ` [PATCH v2 4/6] ARM: sunxi: Remove init_machine callback Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
2014-05-07 2:44 ` [PATCH v2 5/6] ARM: sunxi: Add A31 reset driver to sunxi_defconfig Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
2014-05-07 2:44 ` [PATCH v2 6/6] ARM: multi_v7: Add Allwinner reset drivers to multi_v7_defconfig Maxime Ripard
2014-05-07 2:44 ` Maxime Ripard
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