From mboxrd@z Thu Jan  1 00:00:00 1970
From: timur@codeaurora.org (Timur Tabi)
Date: Tue, 3 May 2016 10:04:59 -0500
Subject: [PATCH RFC] Watchdog: sbsa_gwdt: Enhance timeout range
In-Reply-To: <5728B9BF.8050501@roeck-us.net>
References: <20da73bb9bdf27993514c1da80fead13dc92932d.1462262900.git.panand@redhat.com>
 <57289594.3050801@codeaurora.org> <20160503132439.GC13045@dhcppc6.redhat.com>
 <5728ABE0.5040000@roeck-us.net> <20160503141717.GD13045@dhcppc6.redhat.com>
 <5728B9BF.8050501@roeck-us.net>
Message-ID: <5728BE1B.5010904@codeaurora.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Guenter Roeck wrote:
>> Most likely it will not be corrupted. But, if ISR has been called it
>> means
>> something went wrong, and watchdog was not kicked for the time
>> programmed as
>> "timeout". So, probably we should be extra careful.
>>
> This logic would apply to _every_ watchdog driver implementing interrupts.
> Actually, it would apply to _all_ kernel code, and the logic could be used
> to introduce hyper-defensive programming all over the place, bloat the
> kernel
> and ultimately make it all but unusable. I do not believe in such
> programming
> in an operating system kernel.
>
> On top of that, the assumption that the kernel would be still sane enough
> to call the interrupt handler, but not sane enough to actually execute it,
> seems to be a bit far-fetched.

Agreed.  Pratyush, have you ever seen any watchdog register get 
corrupted, like you describe?  It just seems like you're imagining a 
problem that has never occurred.

-- 
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum, a Linux Foundation collaborative project.