From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Tue, 6 Mar 2018 18:48:44 +0200
Subject: drm: Reject replacing property enum values
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Git-commit: 6f881d04f3f5112e1c4e913a4bfb22bb30e0c9e0
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

If the property already has the enum value WARN and bail.
Replacing enum values doesn't make sense to me.

Throw out the pointless list_empty() while at it.

Cc: Daniel Vetter <daniel@ffwll.ch>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180306164849.2862-1-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_property.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

--- a/drivers/gpu/drm/drm_property.c
+++ b/drivers/gpu/drm/drm_property.c
@@ -390,14 +390,9 @@ int drm_property_add_enum(struct drm_pro
 			(value > 63))
 		return -EINVAL;
 
-	if (!list_empty(&property->enum_list)) {
-		list_for_each_entry(prop_enum, &property->enum_list, head) {
-			if (prop_enum->value == value) {
-				strncpy(prop_enum->name, name, DRM_PROP_NAME_LEN);
-				prop_enum->name[DRM_PROP_NAME_LEN-1] = '\0';
-				return 0;
-			}
-		}
+	list_for_each_entry(prop_enum, &property->enum_list, head) {
+		if (WARN_ON(prop_enum->value == value))
+			return -EINVAL;
 	}
 
 	prop_enum = kzalloc(sizeof(struct drm_property_enum), GFP_KERNEL);