[PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart.

[Sebastian Capella]

Quoting Sebastian Capella (2014-02-24 15:13:45)
> Quoting Russell King - ARM Linux (2014-02-22 02:26:17)
> > On Tue, Feb 18, 2014 at 05:52:07PM -0800, Sebastian Capella wrote:
> > > From: Russ Dill <Russ.Dill at ti.com>
> > > 
> > > This adds the ability to run soft_restart with local_irq/fiq_disable
> > > already called. This is helpful for the hibernation code paths.
> > 
> > I'd rather keep this simple.  There's no problem with calling soft_restart
> > with interrupts already disabled.  local_irq_disable()/local_fiq_disable()
> > there should be harmless.
> 
> Hi Russell,
> 
> I'm observing a data abort loop when I replace this call:
> 
> In the local_irq_disable, it ends up calling trace_hardirqs_off
> (CONFIG_TRACE_IRQFLAGS_SUPPORT is enabled), which calls
> trace_hardirqs_off_caller which checks lockdep_recursion in the
> current task, but we've switched to a temporary stack with the
> call_with_stack, and get_current is returning NULL.  This
> triggers a data abort, which calls trace_hardirqs_off
> again and so on.
> 
> Do you have any suggestions here?

I'll go ahead and send v2, leaving the soft_restart_noirq in place for
now since it's already past midnight in Surrey.

Thanks!

Sebastian