diff --git a/arch/arm/mach-omap1/id.c b/arch/arm/mach-omap1/id.c
index 52de382fc804..bfabc065d331 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 d85c24918c17..75fb6c006e86 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);