[RFC PATCH 3/6] arm: Support restart through restart notifier call chain

[Russell King - ARM Linux]

On Mon, Jun 30, 2014 at 12:11:36PM -0700, Guenter Roeck wrote:
> The kernel core now supports a notifier call chain for system
> restart functions.
> 
> With this change, the arm_pm_restart callback is now optional,
> so check if it is set before calling it.
> 
> Signed-off-by: Guenter Roeck <linux at roeck-us.net>
> ---
>  arch/arm/kernel/process.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index 81ef686..93765f2 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -32,6 +32,7 @@
>  #include <linux/hw_breakpoint.h>
>  #include <linux/leds.h>
>  #include <linux/reboot.h>
> +#include <linux/watchdog.h>
>  
>  #include <asm/cacheflush.h>
>  #include <asm/idmap.h>
> @@ -230,7 +231,10 @@ void machine_restart(char *cmd)
>  	local_irq_disable();
>  	smp_send_stop();
>  
> -	arm_pm_restart(reboot_mode, cmd);
> +	if (arm_pm_restart)
> +		arm_pm_restart(reboot_mode, cmd);
> +
> +	blocking_notifier_call_chain(&restart_notifier_list, reboot_mode, cmd);

One or the other please, because there could (and I think there are)
some implementations which tell stuff to power down, and then continue
into the mdelay() below.  In such situations, we don't want to call
the notifier.

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