Re: [PATCH 1/3] Implement arch disable/enable irq hooks.

Scott Wood writes:

These hooks ensure that a decrementer interrupt is not pending when
suspending; otherwise, problems may occur.  For example, with deep sleep
on the 831x, a pending decrementer will cause a system freeze because the
SoC thinks the decrementer interrupt would have woken the system, but the
core must have interrupts disabled due to the setup required for deep
sleep.

+	set_dec(0x7fffffff);
+	local_irq_disable();
+	set_dec(0x7fffffff);

It might be better to use hard_irq_disable rather than
local_irq_disable here, since I think we will need that on 64-bit (and
on 32-bit if we ever do lazy irq disabling there).

+/* Overrides the weak version in kernel/power/main.c */
+void arch_suspend_disable_irqs(void)
+{
+	if (ppc_md.suspend_disable_irqs)
+		ppc_md.suspend_disable_irqs();
+	else
+		generic_suspend_disable_irqs();

Any particular reason why we need a ppc_md hook here?  Do we expect
some platform to need to do something different?

Paul.