ALSA: hda - Set codec to D3 at reboot/shutdown on Thinkpads

Lenovo Thinkpads with Realtek codecs may still have some loud
crackling noises at reboot/shutdown even though a few previous fixes
have been applied.  It's because the previous fix (disabling the
default shutup callback) takes effect only at transition of the codec
power state.  Meanwhile, at reboot or shutdown, we don't take down the
codec power as default, thus it triggers the same problem unless the
codec is powered down casually by runtime PM.

This patch tries to address the issue.  It gives two things:
- implement the separate reboot_notify hook to struct alc_spec, and
  call it optionally if defined.
- turn off the codec to D3 for Thinkpad models via this new callback

Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=958439
Reported-and-tested-by: Benjamin Poirier <bpoirier@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 531065e..5a79c7a 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -111,6 +111,7 @@
 	void (*power_hook)(struct hda_codec *codec);
 #endif
 	void (*shutup)(struct hda_codec *codec);
+	void (*reboot_notify)(struct hda_codec *codec);
 
 	int init_amp;
 	int codec_variant;	/* flag for other variants */
@@ -773,6 +774,25 @@
 		snd_hda_shutup_pins(codec);
 }
 
+static void alc_reboot_notify(struct hda_codec *codec)
+{
+	struct alc_spec *spec = codec->spec;
+
+	if (spec && spec->reboot_notify)
+		spec->reboot_notify(codec);
+	else
+		alc_shutup(codec);
+}
+
+/* power down codec to D3 at reboot/shutdown; set as reboot_notify ops */
+static void alc_d3_at_reboot(struct hda_codec *codec)
+{
+	snd_hda_codec_set_power_to_all(codec, codec->core.afg, AC_PWRST_D3);
+	snd_hda_codec_write(codec, codec->core.afg, 0,
+			    AC_VERB_SET_POWER_STATE, AC_PWRST_D3);
+	msleep(10);
+}
+
 #define alc_free	snd_hda_gen_free
 
 #ifdef CONFIG_PM
@@ -818,7 +838,7 @@
 	.suspend = alc_suspend,
 	.check_power_status = snd_hda_gen_check_power_status,
 #endif
-	.reboot_notify = alc_shutup,
+	.reboot_notify = alc_reboot_notify,
 };
 
 
@@ -4199,6 +4219,7 @@
 
 	if (action == HDA_FIXUP_ACT_PRE_PROBE) {
 		spec->shutup = alc_no_shutup; /* reduce click noise */
+		spec->reboot_notify = alc_d3_at_reboot; /* reduce noise */
 		spec->parse_flags = HDA_PINCFG_NO_HP_FIXUP;
 		codec->power_save_node = 0; /* avoid click noises */
 		snd_hda_apply_pincfgs(codec, pincfgs);