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Commit a52ff34e authored by Takashi Iwai's avatar Takashi Iwai
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ALSA: hda - Manage power well properly for resume 

For SKL and later Intel chips, we control the power well per codec
basis via link_power callback since the commit [03b135ce: ALSA:
hda - remove dependency on i915 power well for SKL].
However, there are a few exceptional cases where the gfx registers are
accessed from the audio driver: namely the wakeup override bit
toggling at (both system and runtime) resume.  This seems causing a
kernel warning when accessed during the power well down (and likely
resulting in the bogus register accesses).

This patch puts the proper power up / down sequence around the resume
code so that the wakeup bit is fiddled properly while the power is
up.  (The other callback, sync_audio_rate, is used only in the PCM
callback, so it's guaranteed in the power-on.)

Also, by this proper power up/down, the instantaneous flip of wakeup
bit in the resume callback that was introduced by the commit
[033ea349: ALSA: hda - Fix Skylake codec timeout] becomes
superfluous, as snd_hdac_display_power() already does it.  So we can
clean it up together.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96214


Fixes: 03b135ce ('ALSA: hda - remove dependency on i915 power well for SKL')
Cc: <stable@vger.kernel.org> # v4.2+
Tested-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 41f5e3bd

sound/pci/hda/hda_intel.c

+20 −12
Original line number Diff line number Diff line
@@ -906,20 +906,23 @@ static int azx_resume(struct device *dev) 
	struct snd_card *card = dev_get_drvdata(dev);

	struct azx *chip;

	struct hda_intel *hda;

	struct hdac_bus *bus;



	if (!card)

		return 0;



	chip = card->private_data;

	hda = container_of(chip, struct hda_intel, chip);

	bus = azx_bus(chip);

	if (chip->disabled || hda->init_failed || !chip->running)

		return 0;



	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL

		&& hda->need_i915_power) {

		snd_hdac_display_power(azx_bus(chip), true);

		snd_hdac_i915_set_bclk(azx_bus(chip));

	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {

		snd_hdac_display_power(bus, true);

		if (hda->need_i915_power)

			snd_hdac_i915_set_bclk(bus);

	}



	if (chip->msi)

		if (pci_enable_msi(pci) < 0)

			chip->msi = 0;
@@ -929,6 +932,11 @@ static int azx_resume(struct device *dev) 


	hda_intel_init_chip(chip, true);



	/* power down again for link-controlled chips */

	if ((chip->driver_caps & AZX_DCAPS_I915_POWERWELL) &&

	    !hda->need_i915_power)

		snd_hdac_display_power(bus, false);



	snd_power_change_state(card, SNDRV_CTL_POWER_D0);



	trace_azx_resume(chip);
@@ -1008,6 +1016,7 @@ static int azx_runtime_resume(struct device *dev) 


	chip = card->private_data;

	hda = container_of(chip, struct hda_intel, chip);

	bus = azx_bus(chip);

	if (chip->disabled || hda->init_failed)

		return 0;
@@ -1015,15 +1024,9 @@ static int azx_runtime_resume(struct device *dev) 
		return 0;



	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {

		bus = azx_bus(chip);

		if (hda->need_i915_power) {

		snd_hdac_display_power(bus, true);

		if (hda->need_i915_power)

			snd_hdac_i915_set_bclk(bus);

		} else {

			/* toggle codec wakeup bit for STATESTS read */

			snd_hdac_set_codec_wakeup(bus, true);

			snd_hdac_set_codec_wakeup(bus, false);

		}

	}



	/* Read STATESTS before controller reset */
@@ -1043,6 +1046,11 @@ static int azx_runtime_resume(struct device *dev) 
	azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) &

			~STATESTS_INT_MASK);



	/* power down again for link-controlled chips */

	if ((chip->driver_caps & AZX_DCAPS_I915_POWERWELL) &&

	    !hda->need_i915_power)

		snd_hdac_display_power(bus, false);



	trace_azx_runtime_resume(chip);

	return 0;

}