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From: Timur Tabi <timur@codeaurora.org>
To: Guenter Roeck <linux@roeck-us.net>, Pratyush Anand <panand@redhat.com>
Cc: fu.wei@linaro.org, Suravee.Suthikulpanit@amd.com, wim@iguana.be,
	linux-arm-kernel@lists.infradead.org,
	linux-watchdog@vger.kernel.org,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] Watchdog: sbsa_gwdt: Enhance timeout range
Date: Tue, 3 May 2016 10:04:59 -0500	[thread overview]
Message-ID: <5728BE1B.5010904@codeaurora.org> (raw)
In-Reply-To: <5728B9BF.8050501@roeck-us.net>

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.

WARNING: multiple messages have this Message-ID (diff)
From: timur@codeaurora.org (Timur Tabi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH RFC] Watchdog: sbsa_gwdt: Enhance timeout range
Date: Tue, 3 May 2016 10:04:59 -0500	[thread overview]
Message-ID: <5728BE1B.5010904@codeaurora.org> (raw)
In-Reply-To: <5728B9BF.8050501@roeck-us.net>

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.

  reply	other threads:[~2016-05-03 15:04 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-03  8:20 [PATCH RFC] Watchdog: sbsa_gwdt: Enhance timeout range Pratyush Anand
2016-05-03  8:20 ` Pratyush Anand
2016-05-03 12:12 ` Timur Tabi
2016-05-03 12:12   ` Timur Tabi
2016-05-03 13:24   ` Pratyush Anand
2016-05-03 13:24     ` Pratyush Anand
2016-05-03 13:47     ` Guenter Roeck
2016-05-03 13:47       ` Guenter Roeck
2016-05-03 14:17       ` Pratyush Anand
2016-05-03 14:17         ` Pratyush Anand
2016-05-03 14:46         ` Guenter Roeck
2016-05-03 14:46           ` Guenter Roeck
2016-05-03 15:04           ` Timur Tabi [this message]
2016-05-03 15:04             ` Timur Tabi
2016-05-03 13:29 ` Guenter Roeck
2016-05-03 13:29   ` Guenter Roeck
2016-05-03 14:38   ` Pratyush Anand
2016-05-03 14:38     ` Pratyush Anand
2016-05-03 15:07     ` Timur Tabi
2016-05-03 15:07       ` Timur Tabi
2016-05-03 15:51       ` Pratyush Anand
2016-05-03 15:51         ` Pratyush Anand
2016-05-03 17:16         ` Guenter Roeck
2016-05-03 17:16           ` Guenter Roeck
2016-05-04 14:14           ` Pratyush Anand
2016-05-04 14:14             ` Pratyush Anand
2016-05-04 14:21             ` Timur Tabi
2016-05-04 14:21               ` Timur Tabi
2016-05-04 15:59               ` Pratyush Anand
2016-05-04 15:59                 ` Pratyush Anand
2016-05-04 16:17                 ` Timur Tabi
2016-05-04 16:17                   ` Timur Tabi
2016-05-05 16:43                   ` Guenter Roeck
2016-05-05 16:43                     ` Guenter Roeck
2016-05-05 18:20                     ` Pratyush Anand
2016-05-05 18:20                       ` Pratyush Anand
2016-05-05 18:20                       ` Pratyush Anand
2016-05-05 18:22                       ` Timur Tabi
2016-05-05 18:22                         ` Timur Tabi
2016-05-05 18:22                         ` Timur Tabi
2016-05-05 23:36                         ` Guenter Roeck
2016-05-05 23:36                           ` Guenter Roeck
2016-05-05 23:36                           ` Guenter Roeck
2016-05-05 23:38                           ` Timur Tabi
2016-05-05 23:38                             ` Timur Tabi
2016-05-05 23:38                             ` Timur Tabi
2016-05-05 23:45                             ` Timur Tabi
2016-05-05 23:45                               ` Timur Tabi
2016-05-05 23:45                               ` Timur Tabi
2016-05-06  0:18                               ` Guenter Roeck
2016-05-06  0:18                                 ` Guenter Roeck
2016-05-06  0:18                                 ` Guenter Roeck
2016-05-05 23:51                             ` Guenter Roeck
2016-05-05 23:51                               ` Guenter Roeck
2016-05-05 23:51                               ` Guenter Roeck

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