struct hdac_hdmi_pcm *pcm = get_hdmi_pcm_from_id(hdmi, pcm_idx);
        struct hdac_hdmi_port *port;
 
+       if (!pcm)
+               return;
+
        if (list_empty(&pcm->port_list))
                return;
 
        struct hdac_hdmi_priv *hdmi = edev->private_data;
        struct hdac_hdmi_pcm *pcm = get_hdmi_pcm_from_id(hdmi, pcm_idx);
 
+       if (!pcm)
+               return false;
+
        if (list_empty(&pcm->port_list))
                return false;
 
        struct hdac_hdmi_pcm *pcm = get_hdmi_pcm_from_id(hdmi, pcm_idx);
        struct hdac_hdmi_port *port;
 
+       if (!pcm)
+               return 0;
+
        if (list_empty(&pcm->port_list))
                return 0;
 
        hdmi_priv->chmap.ops.is_pcm_attached = is_hdac_hdmi_pcm_attached;
        hdmi_priv->chmap.ops.get_spk_alloc = hdac_hdmi_get_spk_alloc;
 
+       if (!hdac_id)
+               return -ENODEV;
+
        if (hdac_id->driver_data)
                hdmi_priv->drv_data =
                        (struct hdac_hdmi_drv_data *)hdac_id->driver_data;