From bf72726358adfedcf1c268690521891809332151 Mon Sep 17 00:00:00 2001
From: Tony Cheng <tony.cheng@amd.com>
Date: Sat, 14 Jan 2017 01:44:52 -0500
Subject: [PATCH] drm/amd/display: assert if mask is 0 in
 set_reg_field_value_ex

-  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>
---
 drivers/gpu/drm/amd/display/dc/dm_services.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dm_services.h b/drivers/gpu/drm/amd/display/dc/dm_services.h
index 11a0abfd34187..052a43af1bd34 100644
--- 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_value_ex(
 	uint32_t mask,
 	uint8_t shift)
 {
+	ASSERT(mask != 0);
 	return (reg_value & ~mask) | (mask & (value << shift));
 }
 
-- 
2.30.2