ALSA: hda - WAKEEN feature enabling for runtime pm

With runtime power save feature enabled, Headphone hotplug
event will not be detected while controller/codec in D3. HDA has
feature WAKEEN to let codec wake up system if controller is in D3 or
system in S3.(HDA Spec 4.5.9.2/3). Codec can send out INT or wake up
controller depending on whether CIE or GIE enabled.(Figure 4, Interupt
structure).

The controller must be in RESET mode after enter runtime-suspend, otherwise
it will not be waken up even if codec send out wake-up event. And STATESTS
will be cleared after controller brought out of RESET mode.

This patch only enable WAKEEN for runtime-suspend(Controller D3) mode,
not for system S3 mode. with tool "evtest", Headphone hotplug events
could be cought and reported successfully.

[fixed an unused variable warning by tiwai]

Signed-off-by: Wang Xingchao <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

sound/pci/hda/hda_intel.c

···
 	struct snd_card *card = dev_get_drvdata(dev);
 	struct azx *chip = card->private_data;
 
+	/* enable controller wake up event */
+	azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) |
+		  STATESTS_INT_MASK);
+
 	azx_stop_chip(chip);
 	azx_enter_link_reset(chip);
 	azx_clear_irq_pending(chip);
···
 {
 	struct snd_card *card = dev_get_drvdata(dev);
 	struct azx *chip = card->private_data;
+	struct hda_bus *bus;
+	struct hda_codec *codec;
+	int status;
 
 	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
 		hda_display_power(true);
+
+	/* Read STATESTS before controller reset */
+	status = azx_readw(chip, STATESTS);
+
 	azx_init_pci(chip);
 	azx_init_chip(chip, 1);
+
+	bus = chip->bus;
+	if (status && bus) {
+		list_for_each_entry(codec, &bus->codec_list, list)
+			if (status & (1 << codec->addr))
+				queue_delayed_work(codec->bus->workq,
+						   &codec->jackpoll_work, codec->jackpoll_interval);
+	}
+
+	/* disable controller Wake Up event*/
+	azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) &
+			~STATESTS_INT_MASK);
+
 	return 0;
 }