[QUANTAL PATCH] ALSA: hda - use both input paths on Conexant auto parser

[David Henningsson]

On the Thinkpad W520 - and probably several other machines with
Conexant 506x chips - the Dock Mic and Mic are connected to the
same two selector nodes. This patch will make Dock Mic take one
selector node and Mic take the other, when possible.

Without the patch, both paths would take the first selector,
leading to the normal Mic's volume being controlled by
"Dock Mic Boost".
(On other machines, this could instead fixup similar problems between
Mic and Line In, for example.)

BugLink: https://bugs.launchpad.net/bugs/1037642
Signed-off-by: David Henningsson <david.henningsson at canonical.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
(cherry picked from commit 739572a545b8ab6faf9e266c3ed83ea202073699,
 linux/kernel/git/tiwai/sound.git)

Signed-off-by: David Henningsson <david.henningsson at canonical.com>
---

Motivation:
 * Bug tagged with regression-release
 * Takashi did not want to send to stable because it renames some mixer element
   (change of behaviour). Since we haven't released 12.10 yet, that argument does
   not apply to us.

 sound/pci/hda/patch_conexant.c |   20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/sound/pci/hda/patch_conexant.c b/sound/pci/hda/patch_conexant.c
index 41f28c8..0c127cf 100644
--- a/sound/pci/hda/patch_conexant.c
+++ b/sound/pci/hda/patch_conexant.c
@@ -3545,8 +3545,9 @@ static int __select_input_connection(struct hda_codec *codec, hda_nid_t mux,
 				     hda_nid_t pin, hda_nid_t *srcp,
 				     bool do_select, int depth)
 {
+	struct conexant_spec *spec = codec->spec;
 	hda_nid_t conn[HDA_MAX_NUM_INPUTS];
-	int i, nums;
+	int startidx, i, nums;
 
 	switch (get_wcaps_type(get_wcaps(codec, mux))) {
 	case AC_WID_AUD_IN:
@@ -3570,14 +3571,25 @@ static int __select_input_connection(struct hda_codec *codec, hda_nid_t mux,
 	depth++;
 	if (depth == 2)
 		return -1;
+
+	/* Try to rotate around connections to avoid one boost controlling
+	   another input path as well */
+	startidx = 0;
+	for (i = 0; i < spec->private_imux.num_items; i++)
+		if (spec->imux_info[i].pin == pin) {
+			startidx = i;
+			break;
+		}
+
 	for (i = 0; i < nums; i++) {
-		int ret  = __select_input_connection(codec, conn[i], pin, srcp,
+		int j = (i + startidx) % nums;
+		int ret  = __select_input_connection(codec, conn[j], pin, srcp,
 						     do_select, depth);
 		if (ret >= 0) {
 			if (do_select)
 				snd_hda_codec_write(codec, mux, 0,
-						    AC_VERB_SET_CONNECT_SEL, i);
-			return i;
+						    AC_VERB_SET_CONNECT_SEL, j);
+			return j;
 		}
 	}
 	return -1;
-- 
1.7.9.5