diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3dd72d4bb4e0e78a3ffb8816c28cac24a8d3f130..9c56e2165b2abad5d2a2fefd2dd869b4b6d89d14 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8420,7 +8420,7 @@ enum skl_power_gate {
 #define  SKL_PW_TO_PG(pw)			((pw) - SKL_DISP_PW_1 + SKL_PG1)
 #define  SKL_FUSE_PG_DIST_STATUS(pg)		(1 << (27 - (pg)))
 
-#define _CNL_AUX_REG_IDX(pw)		((pw - 1) >> 4)
+#define _CNL_AUX_REG_IDX(pw)		((pw) - 9)
 #define _CNL_AUX_ANAOVRD1_B		0x162250
 #define _CNL_AUX_ANAOVRD1_C		0x162210
 #define _CNL_AUX_ANAOVRD1_D		0x1622D0