From: Tony Cheng <tony.cheng@amd.com>
Date: Sat, 14 Jan 2017 01:44:52 -0500
Subject: drm/amd/display: assert if mask is 0 in set_reg_field_value_ex
Git-commit: bf72726358adfedcf1c268690521891809332151
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

-  mask = 0 means something is wrong in caller and no register field will be updated

Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/dc/dm_services.h |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/amd/display/dc/dm_services.h
+++ b/drivers/gpu/drm/amd/display/dc/dm_services.h
@@ -165,6 +165,7 @@ static inline uint32_t set_reg_field_val
 	uint32_t mask,
 	uint8_t shift)
 {
+	ASSERT(mask != 0);
 	return (reg_value & ~mask) | (mask & (value << shift));
 }