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Date: Wed, 30 Jul 2014 13:53:02 -0700
From: Guenter Roeck <linux@roeck-us.net>
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To: Stephen Boyd <sboyd@codeaurora.org>
CC: linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Ingo Molnar <mingo@kernel.org>, Russell King <linux@arm.linux.org.uk>,
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        Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>,
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        Maxime Ripard <maxime.ripard@free-electrons.com>,
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        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v5 1/7] kernel: Add support for kernel restart handler
 call chain
References: <1405668856-13738-1-git-send-email-linux@roeck-us.net> <1405668856-13738-2-git-send-email-linux@roeck-us.net> <53D95330.1050904@codeaurora.org>
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On 07/30/2014 01:18 PM, Stephen Boyd wrote:
> On 07/18/14 00:34, Guenter Roeck wrote:
>> +/**
>> + *	do_kernel_restart - Execute kernel restart handler call chain
>> + *
>> + *	Calls functions registered with register_restart_handler.
>> + *
>> + *	Expected to be called from machine_restart as last step of the restart
>> + *	sequence.
>> + *
>> + *	Restarts the system immediately if a restart handler function has been
>> + *	registered. Otherwise does nothing.
>> + */
>> +void do_kernel_restart(char *cmd)
>> +{
>> +	blocking_notifier_call_chain(&restart_handler_list, reboot_mode, cmd);
>> +}
>
> Has this been tested with scheduling while atomic checking
> (CONFIG_DEBUG_ATOMIC_SLEEP) or lockdep (CONFIG_PROVE_LOCKING)? ARM would
> call this with irqs disabled and blocking_notifier_call_chain() would
> spit out a warning when it tries to down_read() on it's semaphore. This
> should probably be an atomic notifier chain instead.
>

Good point. I'll update the code accordingly.

I'll wait for additional comments until early next week to avoid unnecessary
churn.

Thanks,
Guenter