Re: [PATCH] ARM: machine_power_off should not return

Russell King - ARM Linux
2014-03-26T00:51:40Z

On Tue, Mar 25, 2014 at 07:45:55PM -0300, Ezequiel Garcia wrote:
> Let's Cc: LAKML, and To: Russell.
>
> Russell, any comments on this?
>
> Without this patch we got the heartbeat's reboot_notifier called twice while
> testing the recent hibernation patches, which was unexpected and produced a
> kernel panic: https://lkml.org/lkml/2014/3/19/363

I don't see why we should make this change. kernel/reboot.c handles
this function returning, so other places should do too.

Even on x86, this function can return:

void machine_power_off(void)
{
machine_ops.power_off();
}

.power_off = native_machine_power_off,

static void native_machine_power_off(void)
{
if (pm_power_off) {
if (!reboot_force)
machine_shutdown();
pm_power_off();
}
/* A fallback in case there is no PM info available */
tboot_shutdown(TB_SHUTDOWN_HALT);
}

void tboot_shutdown(u32 shutdown_type)
{
void (*shutdown)(void);

if (!tboot_enabled())
return;

Therefore, I'd say... it's a bug in the hibernation code - or we probably
have many buggy architectures. I'd suggest fixing the hibernation code
rather than stuffing some workaround like an endless loop into every
architecture.

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