From: Kevin Hilman <khilman@deeprootsystems.com>
To: "Varadarajan, Charulatha" <charu@ti.com>
Cc: Tony Lindgren <tony@atomide.com>,
"Cousson, Benoit" <b-cousson@ti.com>,
"Shilimkar, Santosh" <santosh.shilimkar@ti.com>,
"Menon, Nishanth" <nm@ti.com>, "wim@iguana.be" <wim@iguana.be>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"paul@pwsan.com" <paul@pwsan.com>,
"Nayak, Rajendra" <rnayak@ti.com>,
"Basak, Partha" <p-basak2@ti.com>
Subject: Re: [PATCH] OMAP2PLUS: WDT: Fix: Disable WDT after reset during init
Date: Fri, 01 Oct 2010 07:43:08 -0700 [thread overview]
Message-ID: <8762xmdldv.fsf@deeprootsystems.com> (raw)
In-Reply-To: <EAF47CD23C76F840A9E7FCE10091EFAB030CDFE06C@dbde02.ent.ti.com> (Charulatha Varadarajan's message of "Fri, 1 Oct 2010 19:03:53 +0530")
"Varadarajan, Charulatha" <charu@ti.com> writes:
> Tony, Benoit, Kevin,
>
>> > >> > >
>> > >> > > I think that disabling it should be done only if the
>> > CONFIG_OMAP_WDT
>> > >> > > is not set.
>> > >> >
>> > >> > How about disabling is done always unless CONFIG_WATCHDOG_NOWAYOUT
>> > >> > is set?
>> > >>
>> > >> As given in the patch description, this patch does a disable of
>> > watchdog
>> > >> timer, during init, to avoid the system rebooting that happens due to
>> > >> enabling of watchdog timer after a reset of the module (during hwmod
>> > init).
>> > >>
>> > >> According to the default WDT registers values, the system reboot
>> would
>> > >> happen in ~10s if watchdog is enabled with default values. Hence,
>> after
>> > >> a WDT module reset during init, the watchdog has to be disabled
>> within
>> > 10s
>> > >> otherwise the system will keep rebooting.
>> > >>
>> > >> Hence irrespective of CONFIG_WATCHDOG_NOWAYOUT/ CONFIG_OMAP_WDT,
>> > >> the watchdog timer needs to be disabled after a WDT reset has
>> happened.
>> > >>
>> > > One more option is to avoid the software reset using the
>> CONFIG_OMAP_WDT
>> > > flag. Something like below.
>> >
>> > This was already proposed by Charu, and rejected.
>> >
>> > Doing this means we have a dependency on particular bootloader init, and
>> > we'd like to get rid of *all* assumptions about what the bootloader does
>> > (or does not do.)
>> >
>> you mean is not depeding on bootloader to disable WDT. Make sense.
>>
>
> Let me know your opinion on how to handle this issue.
IMO, we should do what your original patch did: always disable the WDT,
just like most/all bootloaders do.
If we want to make changes later to support product needs (like no
disable on boot, etc.) that is a separate issue and should be done in a
separate patch.
Kevin
WARNING: multiple messages have this Message-ID (diff)
From: khilman@deeprootsystems.com (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] OMAP2PLUS: WDT: Fix: Disable WDT after reset during init
Date: Fri, 01 Oct 2010 07:43:08 -0700 [thread overview]
Message-ID: <8762xmdldv.fsf@deeprootsystems.com> (raw)
In-Reply-To: <EAF47CD23C76F840A9E7FCE10091EFAB030CDFE06C@dbde02.ent.ti.com> (Charulatha Varadarajan's message of "Fri, 1 Oct 2010 19:03:53 +0530")
"Varadarajan, Charulatha" <charu@ti.com> writes:
> Tony, Benoit, Kevin,
>
>> > >> > >
>> > >> > > I think that disabling it should be done only if the
>> > CONFIG_OMAP_WDT
>> > >> > > is not set.
>> > >> >
>> > >> > How about disabling is done always unless CONFIG_WATCHDOG_NOWAYOUT
>> > >> > is set?
>> > >>
>> > >> As given in the patch description, this patch does a disable of
>> > watchdog
>> > >> timer, during init, to avoid the system rebooting that happens due to
>> > >> enabling of watchdog timer after a reset of the module (during hwmod
>> > init).
>> > >>
>> > >> According to the default WDT registers values, the system reboot
>> would
>> > >> happen in ~10s if watchdog is enabled with default values. Hence,
>> after
>> > >> a WDT module reset during init, the watchdog has to be disabled
>> within
>> > 10s
>> > >> otherwise the system will keep rebooting.
>> > >>
>> > >> Hence irrespective of CONFIG_WATCHDOG_NOWAYOUT/ CONFIG_OMAP_WDT,
>> > >> the watchdog timer needs to be disabled after a WDT reset has
>> happened.
>> > >>
>> > > One more option is to avoid the software reset using the
>> CONFIG_OMAP_WDT
>> > > flag. Something like below.
>> >
>> > This was already proposed by Charu, and rejected.
>> >
>> > Doing this means we have a dependency on particular bootloader init, and
>> > we'd like to get rid of *all* assumptions about what the bootloader does
>> > (or does not do.)
>> >
>> you mean is not depeding on bootloader to disable WDT. Make sense.
>>
>
> Let me know your opinion on how to handle this issue.
IMO, we should do what your original patch did: always disable the WDT,
just like most/all bootloaders do.
If we want to make changes later to support product needs (like no
disable on boot, etc.) that is a separate issue and should be done in a
separate patch.
Kevin
next prev parent reply other threads:[~2010-10-01 14:43 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-30 8:11 [PATCH] OMAP2PLUS: WDT: Fix: Disable WDT after reset during init Varadarajan, Charulatha
2010-09-30 8:11 ` Varadarajan, Charulatha
2010-09-30 9:07 ` Cousson, Benoit
2010-09-30 9:07 ` Cousson, Benoit
2010-09-30 13:55 ` Kevin Hilman
2010-09-30 13:55 ` Kevin Hilman
2010-09-30 14:12 ` Cousson, Benoit
2010-09-30 14:12 ` Cousson, Benoit
2010-09-30 14:51 ` Kevin Hilman
2010-09-30 14:51 ` Kevin Hilman
2010-09-30 15:07 ` Tony Lindgren
2010-09-30 15:07 ` Tony Lindgren
2010-09-30 15:55 ` Varadarajan, Charulatha
2010-09-30 15:55 ` Varadarajan, Charulatha
2010-09-30 16:32 ` Varadarajan, Charulatha
2010-09-30 16:32 ` Varadarajan, Charulatha
2010-09-30 16:43 ` Paul Walmsley
2010-09-30 16:43 ` Paul Walmsley
2010-09-30 16:51 ` Tony Lindgren
2010-09-30 16:51 ` Tony Lindgren
2010-09-30 16:46 ` Cousson, Benoit
2010-09-30 16:46 ` Cousson, Benoit
2010-09-30 16:57 ` Cousson, Benoit
2010-09-30 16:57 ` Cousson, Benoit
2010-09-30 17:06 ` Varadarajan, Charulatha
2010-09-30 17:06 ` Varadarajan, Charulatha
2010-09-30 17:05 ` Shilimkar, Santosh
2010-09-30 17:05 ` Shilimkar, Santosh
2010-09-30 17:11 ` Kevin Hilman
2010-09-30 17:11 ` Kevin Hilman
2010-10-01 7:26 ` Shilimkar, Santosh
2010-10-01 7:26 ` Shilimkar, Santosh
2010-10-01 13:33 ` Varadarajan, Charulatha
2010-10-01 13:33 ` Varadarajan, Charulatha
2010-10-01 14:43 ` Kevin Hilman [this message]
2010-10-01 14:43 ` Kevin Hilman
2010-10-01 17:12 ` Cousson, Benoit
2010-10-01 17:12 ` Cousson, Benoit
2010-09-30 13:57 ` Kevin Hilman
2010-09-30 13:57 ` Kevin Hilman
2010-09-30 13:57 ` Kevin Hilman
2010-09-30 16:36 ` Varadarajan, Charulatha
2010-09-30 16:36 ` Varadarajan, Charulatha
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