diff --git a/drivers/phy/mediatek/phy-mtk-io.h b/drivers/phy/mediatek/phy-mtk-io.h
index a723d4afc9b4..d20ad5e5be81 100644
--- a/drivers/phy/mediatek/phy-mtk-io.h
+++ b/drivers/phy/mediatek/phy-mtk-io.h
@@ -36,10 +36,11 @@ static inline void mtk_phy_update_bits(void __iomem *reg, u32 mask, u32 val)
 	writel(tmp, reg);
 }
 
-/* field @mask should be constant and continuous */
-static inline void mtk_phy_update_field(void __iomem *reg, u32 mask, u32 val)
-{
-	mtk_phy_update_bits(reg, mask, FIELD_PREP(mask, val));
-}
+/* field @mask shall be constant and continuous */
+#define mtk_phy_update_field(reg, mask, val) \
+({ \
+	typeof(mask) mask_ = (mask);	\
+	mtk_phy_update_bits(reg, mask_, FIELD_PREP(mask_, val)); \
+})
 
 #endif