diff --git a/arch/arm/mach-omap1/id.c b/arch/arm/mach-omap1/id.c
index 52de382fc8047148f272dd57d7dd01354ec33801..bfabc065d331e3e0586020a22b7830d8345be318 100644
--- a/arch/arm/mach-omap1/id.c
+++ b/arch/arm/mach-omap1/id.c
@@ -65,6 +65,7 @@ static struct omap_id omap_ids[] __initdata = {
 
 unsigned int omap_rev(void)
 {
+	WARN_ON_ONCE(!omap_revision || omap_revision == -1);
 	return omap_revision;
 }
 EXPORT_SYMBOL(omap_rev);
diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
index d85c24918c177d176fd191aa1ebcfaff5ce90f74..75fb6c006e865b1501db71d64da883b5db2a7d42 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -46,6 +46,7 @@ u32 omap_features;
 
 unsigned int omap_rev(void)
 {
+	WARN_ON_ONCE(!omap_revision || omap_revision == -1);
 	return omap_revision;
 }
 EXPORT_SYMBOL(omap_rev);