memory: emif: use restart if power_off not present when out of spec

Some machine or kernel variants might have missed implementation
of power off handlers. We DONOT want to let the system be in
"out of spec" state in this condition. So, WARN and attempt
a machine restart in the hopes of clearing the out-of-spec
temperature condition.

NOTE: This is not the safest option, but safer than leaving the
system in unstable conditions.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/memory/emif.c

@@ -25,6 +25,7 @@
 #include <linux/module.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
+#include <linux/pm.h>
 #include <memory/jedec_ddr.h>
 #include "emif.h"
 #include "of_memory.h"
@@ -1015,7 +1016,14 @@ static irqreturn_t emif_threaded_isr(int irq, void *dev_id)
 
 	if (emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN) {
 		dev_emerg(emif->dev, "SDRAM temperature exceeds operating limit.. Needs shut down!!!\n");
-		kernel_power_off();
+
+		/* If we have Power OFF ability, use it, else try restarting */
+		if (pm_power_off) {
+			kernel_power_off();
+		} else {
+			WARN(1, "FIXME: NO pm_power_off!!! trying restart\n");
+			kernel_restart("SDRAM Over-temp Emergency restart");
+		}
 		return IRQ_HANDLED;
 	}