AC_VERB_SET_DIGI_CONVERT_2,
                                          val >> 8);
 
-               for (d = codec->slave_dig_outs; *d; d++) {
-                       snd_hda_codec_write_cache(codec, *d, 0,
+               if (codec->slave_dig_outs)
+                       for (d = codec->slave_dig_outs; *d; d++) {
+                               snd_hda_codec_write_cache(codec, *d, 0,
                                          AC_VERB_SET_DIGI_CONVERT_1,
                                          val & 0xff);
-                       snd_hda_codec_write_cache(codec, *d, 0,
+                               snd_hda_codec_write_cache(codec, *d, 0,
                                          AC_VERB_SET_DIGI_CONVERT_2,
                                          val >> 8);
-               }
+                       }
        }
 
        mutex_unlock(&codec->spdif_mutex);
                                          AC_VERB_SET_DIGI_CONVERT_1,
                                          val & 0xff);
 
-               for (d = codec->slave_dig_outs; *d; d++)
-                       snd_hda_codec_write_cache(codec, *d, 0,
+               if (codec->slave_dig_outs)
+                       for (d = codec->slave_dig_outs; *d; d++)
+                               snd_hda_codec_write_cache(codec, *d, 0,
                                          AC_VERB_SET_DIGI_CONVERT_1,
                                          val & 0xff);
                /* unmute amp switch (if any) */
                snd_hda_codec_write_cache(codec, nid, 0,
                                          AC_VERB_SET_DIGI_CONVERT_1, val);
 
-               for (d = codec->slave_dig_outs; *d; d++)
-                       snd_hda_codec_write_cache(codec, *d, 0,
+               if (codec->slave_dig_outs)
+                       for (d = codec->slave_dig_outs; *d; d++)
+                               snd_hda_codec_write_cache(codec, *d, 0,
                                          AC_VERB_SET_DIGI_CONVERT_1, val);
        }
        mutex_unlock(&codec->spdif_mutex);
                snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_DIGI_CONVERT_1,
                            codec->spdif_ctls & ~AC_DIG1_ENABLE & 0xff);
 
-               for (d = codec->slave_dig_outs; *d; d++)
-                       snd_hda_codec_write(codec, *d, 0,
-                                       AC_VERB_SET_DIGI_CONVERT_1,
+               if (codec->slave_dig_outs)
+                       for (d = codec->slave_dig_outs; *d; d++)
+                               snd_hda_codec_write(codec, *d, 0,
+                                   AC_VERB_SET_DIGI_CONVERT_1,
                                    codec->spdif_ctls & ~AC_DIG1_ENABLE & 0xff);
        }
        snd_hda_codec_setup_stream(codec, nid, stream_tag, 0, format);
                snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_DIGI_CONVERT_1,
                                    codec->spdif_ctls & 0xff);
 
-               for (d = codec->slave_dig_outs; *d; d++)
-                       snd_hda_codec_write(codec, *d, 0,
-                                       AC_VERB_SET_DIGI_CONVERT_1,
+               if (codec->slave_dig_outs)
+                       for (d = codec->slave_dig_outs; *d; d++)
+                               snd_hda_codec_write(codec, *d, 0,
+                                   AC_VERB_SET_DIGI_CONVERT_1,
                                    codec->spdif_ctls & 0xff);
        }