diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index f865756..f3c992e 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -378,7 +378,7 @@
 void gpmc_cs_free(int cs)
 {
 	spin_lock(&gpmc_mem_lock);
-	if (cs >= GPMC_CS_NUM || !gpmc_cs_reserved(cs)) {
+	if (cs >= GPMC_CS_NUM || cs < 0 || !gpmc_cs_reserved(cs)) {
 		printk(KERN_ERR "Trying to free non-reserved GPMC CS%d\n", cs);
 		BUG();
 		spin_unlock(&gpmc_mem_lock);