From a7e6fb99150ebb2852ebd0e7bad9ce37cc9a79dd Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Mon, 20 Oct 2014 18:08:50 +0200
Subject: ALSA: control: Allow to pass items zero to snd_ctl_enum_info()

Although this is weird, some drivers want to allow empty control
elements intentionally, e.g. the number of items may change depending
on the firmware status.  Let the function simply returning in such a
case.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/core/control.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/core/control.c b/sound/core/control.c
index f95df84437e1..5c35bbaf881e 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1745,6 +1745,8 @@ int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
 	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
 	info->count = channels;
 	info->value.enumerated.items = items;
+	if (!items)
+		return 0;
 	if (info->value.enumerated.item >= items)
 		info->value.enumerated.item = items - 1;
 	WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
-- 
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