ALSA: hda - stop setup_dig_out_stream() causing clicks

Starting audio or seeking in various music players causes
setup_dig_out_stream() to be called, which resets the SPDIF stream,
which caused one DAC (but not another) to make a clicking noise every
time.

This patch ensures the reset only happens when it needs to, which is
when the format changes, and makes the code a little more readable.

Signed-off-by: Laurence Darby <ldarby@tuffmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 15 insertions, 5 deletions

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 2da787519513..569bc05aad6c 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -4816,10 +4816,20 @@ EXPORT_SYMBOL_HDA(snd_hda_input_mux_put);
 static void setup_dig_out_stream(struct hda_codec *codec, hda_nid_t nid,
                                  unsigned int stream_tag, unsigned int format)
 {
-        struct hda_spdif_out *spdif = snd_hda_spdif_out_of_nid(codec, nid);
-
-        /* turn off SPDIF once; otherwise the IEC958 bits won't be updated */
-        if (codec->spdif_status_reset && (spdif->ctls & AC_DIG1_ENABLE))
+        struct hda_spdif_out *spdif;
+        unsigned int curr_fmt;
+        bool reset;
+
+        spdif = snd_hda_spdif_out_of_nid(codec, nid);
+        curr_fmt = snd_hda_codec_read(codec, nid, 0,
+                                      AC_VERB_GET_STREAM_FORMAT, 0);
+        reset = codec->spdif_status_reset &&
+                (spdif->ctls & AC_DIG1_ENABLE) &&
+                curr_fmt != format;
+
+        /* turn off SPDIF if needed; otherwise the IEC958 bits won't be
+           updated */
+        if (reset)
                 set_dig_out_convert(codec, nid,
                                     spdif->ctls & ~AC_DIG1_ENABLE & 0xff,
                                     -1);
@@ -4831,7 +4841,7 @@ static void setup_dig_out_stream(struct hda_codec *codec, hda_nid_t nid,
                                                    format);
         }
         /* turn on again (if needed) */
-        if (codec->spdif_status_reset && (spdif->ctls & AC_DIG1_ENABLE))
+        if (reset)
                 set_dig_out_convert(codec, nid,
                                     spdif->ctls & 0xff, -1);
 }