linux-kernel - [PATCH AUTOSEL 4.19 130/167] ALSA: hda - Don't resume forcibly i915 HDMI/DP codec

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Date:   Tue,  3 Sep 2019 12:24:42 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Takashi Iwai <tiwai@...e.de>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.19 130/167] ALSA: hda - Don't resume forcibly i915 HDMI/DP codec

From: Takashi Iwai <tiwai@...e.de>

[ Upstream commit 4914da2fb0c89205790503f20dfdde854f3afdd8 ]

We apply the codec resume forcibly at system resume callback for
updating and syncing the jack detection state that may have changed
during sleeping.  This is, however, superfluous for the codec like
Intel HDMI/DP, where the jack detection is managed via the audio
component notification; i.e. the jack state change shall be reported
sooner or later from the graphics side at mode change.

This patch changes the codec resume callback to avoid the forcible
resume conditionally with a new flag, codec->relaxed_resume, for
reducing the resume time.  The flag is set in the codec probe.

Although this doesn't fix the entire bug mentioned in the bugzilla
entry below, it's still a good optimization and some improvements are
seen.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201901
Cc: <stable@...r.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@...e.de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 sound/pci/hda/hda_codec.c  | 8 ++++++--
 sound/pci/hda/hda_codec.h  | 2 ++
 sound/pci/hda/patch_hdmi.c | 6 +++++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index a6233775e779f..82b0dc9f528f0 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2947,15 +2947,19 @@ static int hda_codec_runtime_resume(struct device *dev)
 #ifdef CONFIG_PM_SLEEP
 static int hda_codec_force_resume(struct device *dev)
 {
+	struct hda_codec *codec = dev_to_hda_codec(dev);
+	bool forced_resume = !codec->relaxed_resume;
 	int ret;
 
 	/* The get/put pair below enforces the runtime resume even if the
 	 * device hasn't been used at suspend time.  This trick is needed to
 	 * update the jack state change during the sleep.
 	 */
-	pm_runtime_get_noresume(dev);
+	if (forced_resume)
+		pm_runtime_get_noresume(dev);
 	ret = pm_runtime_force_resume(dev);
-	pm_runtime_put(dev);
+	if (forced_resume)
+		pm_runtime_put(dev);
 	return ret;
 }
 
diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index acacc19002658..2003403ce1c82 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -261,6 +261,8 @@ struct hda_codec {
 	unsigned int auto_runtime_pm:1; /* enable automatic codec runtime pm */
 	unsigned int force_pin_prefix:1; /* Add location prefix */
 	unsigned int link_down_at_suspend:1; /* link down at runtime suspend */
+	unsigned int relaxed_resume:1;	/* don't resume forcibly for jack */
+
 #ifdef CONFIG_PM
 	unsigned long power_on_acct;
 	unsigned long power_off_acct;
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 35931a18418f3..e4fbfb5557ab7 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2293,8 +2293,10 @@ static void generic_hdmi_free(struct hda_codec *codec)
 	struct hdmi_spec *spec = codec->spec;
 	int pin_idx, pcm_idx;
 
-	if (codec_has_acomp(codec))
+	if (codec_has_acomp(codec)) {
 		snd_hdac_acomp_register_notifier(&codec->bus->core, NULL);
+		codec->relaxed_resume = 0;
+	}
 
 	for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) {
 		struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);
@@ -2550,6 +2552,8 @@ static void register_i915_notifier(struct hda_codec *codec)
 	spec->drm_audio_ops.pin_eld_notify = intel_pin_eld_notify;
 	snd_hdac_acomp_register_notifier(&codec->bus->core,
 					&spec->drm_audio_ops);
+	/* no need for forcible resume for jack check thanks to notifier */
+	codec->relaxed_resume = 1;
 }
 
 /* setup_stream ops override for HSW+ */
-- 
2.20.1