FAILED: patch "[PATCH] drm/i915/audio: fix check for av_enc_map overflow" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Jani Nikula <[email protected]>
Date: Wed, 14 Feb 2018 19:38:40 +0200
Subject: [PATCH] drm/i915/audio: fix check for av_enc_map overflow

Turns out -1 >= ARRAY_SIZE() is always true. Move the bounds check where we know pipe >= 0 and next to the array indexing where it makes most sense.

index 522d54fecb53..4a01f62a392d 100644
@@ -779,11 +779,11 @@ static struct intel_encoder *get_saved_enc(struct drm_i915_private *dev_priv,
 {
 	struct intel_encoder *encoder;
 
-	if (WARN_ON(pipe >= ARRAY_SIZE(dev_priv->av_enc_map)))
-		return NULL;
-
 	/* MST */
 	if (pipe >= 0) {
+		if (WARN_ON(pipe >= ARRAY_SIZE(dev_priv->av_enc_map)))
+			return NULL;
+
 		encoder = dev_priv->av_enc_map[pipe];
 		/*
 		 * when bootup, audio driver may not know it is