commit b1b2c798b2943c887bd063bbe415aa2e48923817
Author: Sven Schnelle <svens@stackframe.org>
Date:   Tue Feb 6 09:17:18 2018 +0100

    ALSA: hda: check eld_ctl pointer before using it
    
    Signed-off-by: Sven Schnelle <svens@stackframe.org>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index b4f1b6e88305..7efe0dc26c7c 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1433,6 +1433,7 @@ static void update_eld(struct hda_codec *codec,
 {
 	struct hdmi_eld *pin_eld = &per_pin->sink_eld;
 	struct hdmi_spec *spec = codec->spec;
+	struct snd_kcontrol *eld_ctl;
 	bool old_eld_valid = pin_eld->eld_valid;
 	bool eld_changed;
 	int pcm_idx = -1;
@@ -1482,11 +1483,13 @@ static void update_eld(struct hda_codec *codec,
 		hdmi_setup_audio_infoframe(codec, per_pin, per_pin->non_pcm);
 	}
 
-	if (eld_changed && pcm_idx >= 0)
+	eld_ctl =  get_hdmi_pcm(spec, pcm_idx)->eld_ctl;
+	if (eld_changed && pcm_idx >= 0 && eld_ctl) {
 		snd_ctl_notify(codec->card,
 			       SNDRV_CTL_EVENT_MASK_VALUE |
 			       SNDRV_CTL_EVENT_MASK_INFO,
-			       &get_hdmi_pcm(spec, pcm_idx)->eld_ctl->id);
+			       &eld_ctl->id);
+	}
 }
 
 /* update ELD and jack state via HD-audio verbs */