ARM: OMAP4: PM: Use custom omap_do_wfi() for default idle.

Default arch_idle() isn't good enough for OMAP4 because of aync bridge errata
and necessity of NOPs post WFI to avoid speculative prefetch aborts.
Hence Use OMAP4 custom omap_do_wfi() hook for default idle.

Later in the series, async bridge errata work-around patch updates the
omap_do_wfi() with necessary interconnects barriers.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

arch/arm/mach-omap2/pm44xx.c

@@ -107,6 +107,24 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 	return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);
 }
 
+/**
+ * omap_default_idle - OMAP4 default ilde routine.'
+ *
+ * Implements OMAP4 memory, IO ordering requirements which can't be addressed
+ * with default arch_idle() hook. Used by all CPUs with !CONFIG_CPUIDLE and
+ * by secondary CPU with CONFIG_CPUIDLE.
+ */
+static void omap_default_idle(void)
+{
+	local_irq_disable();
+	local_fiq_disable();
+
+	omap_do_wfi();
+
+	local_fiq_enable();
+	local_irq_enable();
+}
+
 /**
  * omap4_pm_init - Init routine for OMAP4 PM
  *
@@ -175,6 +193,9 @@ static int __init omap4_pm_init(void)
 	suspend_set_ops(&omap_pm_ops);
 #endif /* CONFIG_SUSPEND */
 
+	/* Overwrite the default arch_idle() */
+	pm_idle = omap_default_idle;
+
 err2:
 	return ret;
 }