From dc854914999d5d52ac1b31740cb0ea8d89d0372e Mon Sep 17 00:00:00 2001
From: Lyude Paul <lyude@redhat.com>
Date: Thu, 6 Sep 2018 17:43:21 -0400
Subject: [PATCH] drm/nouveau: Check backlight IDs are >= 0, not > 0
Git-commit: dc854914999d5d52ac1b31740cb0ea8d89d0372e
Patch-mainline: v4.20-rc1
References: bsc#1051510

Remember, ida IDs start at 0, not 1!

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/nouveau/nouveau_backlight.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -116,7 +116,7 @@ nv40_backlight_init(struct drm_connector
 				       &nv40_bl_ops, &props);
 
 	if (IS_ERR(bd)) {
-		if (bl_connector.id > 0)
+		if (bl_connector.id >= 0)
 			ida_simple_remove(&bl_ida, bl_connector.id);
 		return PTR_ERR(bd);
 	}
@@ -249,7 +249,7 @@ nv50_backlight_init(struct drm_connector
 				       nv_encoder, ops, &props);
 
 	if (IS_ERR(bd)) {
-		if (bl_connector.id > 0)
+		if (bl_connector.id >= 0)
 			ida_simple_remove(&bl_ida, bl_connector.id);
 		return PTR_ERR(bd);
 	}