Re: [PATCH] it87_wdt: Work around non-working CIR interrupts

From: Guenter Roeck
Date: Sun Mar 09 2014 - 22:29:29 EST


On 03/06/2014 01:36 AM, Marc van der Wal wrote:
From: Marc van der Wal <x0r+kernel@xxxxxx>

On some hardware platforms, the it87_wdt watchdog resets the machine
despite the watchdog daemon running and writing to /dev/watchdog.

This is due to Consumer IR buffer underrun interrupts being used as
triggers to reset the timer. On some buggy hardware implementations
such as the iEi AFL-12A-N270 single-board computer, this method does
not work.

However, resetting the timer by writing its original timeout value in
its configuration register over and over again suppresses the unwanted
reboots.

Add a module option (nocir), 0 by default in order not to break existing
setups. Setting it to 1 enables the workaround.

Fixes bug #42801 <https://bugzilla.kernel.org/show_bug.cgi?id=42801>.
Tested primarily on Linux 3.5.7, applies cleanly on Linux 3.13.5.

Signed-off-by: Marc van der Wal <x0r+kernel@xxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>


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