From 27a451e83e78e1167f58cddba189fae4b4fa0d5b Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Thu, 17 Aug 2017 23:03:23 +0100
Subject: [PATCH] drm/nouveau/kms/nv50: perform null check on msto[i] rathern than msto
Git-commit: 27a451e83e78e1167f58cddba189fae4b4fa0d5b
Patch-mainline: v4.14-rc1
References: bsc#1051510

The null check on the array msto is incorrect since msto is never
null. The null check should be instead on msto[i] since this is
being dereferenced in the call to drm_mode_connector_attach_encoder.

Thanks to Emil Velikov for pointing out the mistake in my original
fix and for suggesting the correct fix.

Detected by CoverityScan, CID#1375915 ("Array compared against 0")

Fixes: f479c0ba4a17 ("drm/nouveau/kms/nv50: initial support for DP 1.2 multi-stream")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/nouveau/nv50_display.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -3141,7 +3141,7 @@ nv50_mstc_new(struct nv50_mstm *mstm, st
 	mstc->connector.funcs->reset(&mstc->connector);
 	nouveau_conn_attach_properties(&mstc->connector);
 
-	for (i = 0; i < ARRAY_SIZE(mstm->msto) && mstm->msto; i++)
+	for (i = 0; i < ARRAY_SIZE(mstm->msto) && mstm->msto[i]; i++)
 		drm_mode_connector_attach_encoder(&mstc->connector, &mstm->msto[i]->encoder);
 
 	drm_object_attach_property(&mstc->connector.base, dev->mode_config.path_property, 0);