ALSA: hda - Add probe_only option

Added probe_only module option to hd-audio driver.
This option specifies whether the driver creates and initializes the
codec-parser after probing.  When this option is set, the driver skips
the codec parsing and initialization but gives you proc and other
accesses.  It's useful to see the initial codec state for debugging.

The default of this value is off, so the default behavior is as same
as before.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index a26ae8c..6613b6b 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -58,6 +58,7 @@
 static int position_fix[SNDRV_CARDS];
 static int bdl_pos_adj[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = -1};
 static int probe_mask[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = -1};
+static int probe_only[SNDRV_CARDS];
 static int single_cmd;
 static int enable_msi;
 
@@ -76,6 +77,8 @@
 MODULE_PARM_DESC(bdl_pos_adj, "BDL position adjustment offset.");
 module_param_array(probe_mask, int, NULL, 0444);
 MODULE_PARM_DESC(probe_mask, "Bitmask to probe codecs (default = -1).");
+module_param_array(probe_only, bool, NULL, 0444);
+MODULE_PARM_DESC(probe_only, "Only probing and no codec initialization.");
 module_param(single_cmd, bool, 0444);
 MODULE_PARM_DESC(single_cmd, "Use single command to communicate with codecs "
 		 "(for debugging only).");
@@ -1224,7 +1227,8 @@
 };
 
 static int __devinit azx_codec_create(struct azx *chip, const char *model,
-				      unsigned int codec_probe_mask)
+				      unsigned int codec_probe_mask,
+				      int no_init)
 {
 	struct hda_bus_template bus_temp;
 	int c, codecs, err;
@@ -1282,7 +1286,7 @@
 	for (c = 0; c < max_slots; c++) {
 		if ((chip->codec_mask & (1 << c)) & codec_probe_mask) {
 			struct hda_codec *codec;
-			err = snd_hda_codec_new(chip->bus, c, &codec);
+			err = snd_hda_codec_new(chip->bus, c, !no_init, &codec);
 			if (err < 0)
 				continue;
 			codecs++;
@@ -2340,7 +2344,8 @@
 	card->private_data = chip;
 
 	/* create codec instances */
-	err = azx_codec_create(chip, model[dev], probe_mask[dev]);
+	err = azx_codec_create(chip, model[dev], probe_mask[dev],
+			       probe_only[dev]);
 	if (err < 0)
 		goto out_free;