ALSA: hda/realtek - Avoid invalid COEFs for ALC271X

commit d3c56568 upstream.

We've seen often problems after suspend/resume on Acer Aspire One
AO725 with ALC271X codec as reported in kernel bugzilla, and it turned
out that some COEFs doesn't work and triggers the codec communication
stall.

Since these magic COEF setups are specific to ALC269VB for some PLL
configurations, the machine works even without these manual
adjustment.  So, let's simply avoid applying them for ALC271X.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=52181Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: return 0]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

sound/pci/hda/patch_realtek.c

@@ -5157,6 +5157,9 @@ static int alc269_fill_coef(struct hda_codec *codec)
 
 	if (spec->codec_variant != ALC269_TYPE_ALC269VB)
 		return 0;
+	/* ALC271X doesn't seem to support these COEFs (bko#52181) */
+	if (!strcmp(codec->chip_name, "ALC271X"))
+		return 0;
 
 	if ((alc_get_coef0(codec) & 0x00ff) < 0x015) {
 		alc_write_coef_idx(codec, 0xf, 0x960b);