[alsa-devel] [PATCH 3/3] ALSA: hda - delay resuming Haswell HDMI codec in system resume

[mengdong.lin at intel.com]

From: Mengdong Lin <mengdong.lin at intel.com>

In system resume, Haswell codec cannot be programmed to D0 before Gfx driver
initializes the display pipeline and audio, which will trigger an unsol event
on the pin with HDMI/DP cable connected. Otherwise, the connected pin will
stay in D3 with right channel muted and thus no sound can be heard.

In this patch, Haswell codec will claim it needs "delaying resume" by setting
flag "support_delay_resume", so system resume will skip it and mark it as
"delay_resumed". On later codec access, Haswell codec will be resumed and
hda_call_codec_resume() will call its set_power_states ops intel_haswell_set_
power_state(). For a delayed resume, this ops will enable and wait for the
unsol event, and then resume the codec. A 300ms timeout is set in case unsol
event is lost.

Signed-off-by: Mengdong Lin <mengdong.lin at intel.com>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index ede8215..f39e374 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -89,6 +89,14 @@ struct hdmi_spec {
 	 */
 	struct hda_multi_out multiout;
 	struct hda_pcm_stream pcm_playback;
+
+#ifdef CONFIG_PM
+	/*
+	 * Non-generic Intel Haswell specific
+	 */
+	unsigned int ready_to_resume:1;
+	wait_queue_head_t resume_wq;
+#endif
 };
 
 
@@ -975,6 +983,13 @@ static void hdmi_intrinsic_event(struct hda_codec *codec, unsigned int res)
 	if (pin_idx < 0)
 		return;
 
+#ifdef CONFIG_PM
+	if (codec->resume_delayed) {
+		spec->ready_to_resume = 1;
+		wake_up(&spec->resume_wq);
+	}
+#endif
+
 	hdmi_present_sense(get_pin(spec, pin_idx), 1);
 	snd_hda_jack_report_sync(codec);
 }
@@ -1725,6 +1740,11 @@ static int generic_hdmi_init(struct hda_codec *codec)
 		hdmi_init_pin(codec, pin_nid);
 		snd_hda_jack_detect_enable(codec, pin_nid, pin_nid);
 	}
+
+#ifdef CONFIG_PM
+	spec->ready_to_resume = 0;
+#endif
+
 	return 0;
 }
 
@@ -1855,6 +1875,61 @@ static const struct hda_fixup hdmi_fixups[] = {
 };
 
 
+#ifdef CONFIG_PM
+static void intel_haswell_wait_ready_to_resume(struct hda_codec *codec)
+{
+	struct hdmi_spec *spec = codec->spec;
+	int pin_idx;
+
+	for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) {
+		struct hdmi_spec_per_pin *per_pin;
+		hda_nid_t pin_nid;
+		struct hda_jack_tbl *jack;
+
+		per_pin = get_pin(spec, pin_idx);
+		pin_nid = per_pin->pin_nid;
+		jack = snd_hda_jack_tbl_get(codec, pin_nid);
+		if (jack)
+			snd_hda_codec_write(codec, pin_nid, 0,
+				 AC_VERB_SET_UNSOLICITED_ENABLE,
+				 AC_USRSP_EN | jack->tag);
+	}
+
+	wait_event_timeout(spec->resume_wq,
+			spec->ready_to_resume, msecs_to_jiffies(300));
+	if (!spec->ready_to_resume)
+		snd_printd(KERN_WARNING "HDMI: Haswell not ready to resume\n");
+}
+
+static void intel_haswell_set_power_state(struct hda_codec *codec, hda_nid_t fg,
+				 unsigned int power_state)
+{
+	if (codec->resume_delayed && power_state ==  AC_PWRST_D0) {
+		intel_haswell_wait_ready_to_resume(codec);
+		codec->resume_delayed = 0;
+	}
+
+	snd_hda_codec_read(codec, fg, 0,
+			AC_VERB_SET_POWER_STATE,
+			power_state);
+
+	snd_hda_codec_set_power_to_all(codec, fg, power_state);
+}
+
+static inline void intel_haswell_allow_delay_resume(struct hda_codec *codec)
+{
+	struct hdmi_spec *spec = codec->spec;
+
+	init_waitqueue_head(&spec->resume_wq);
+	codec->support_delay_resume = 1;
+
+	codec->patch_ops.set_power_state =
+				intel_haswell_set_power_state;
+}
+#else
+define intel_haswell_allow_delay_resume NULL
+#endif
+
 static int patch_generic_hdmi(struct hda_codec *codec)
 {
 	struct hdmi_spec *spec;
@@ -1878,6 +1953,10 @@ static int patch_generic_hdmi(struct hda_codec *codec)
 		return -EINVAL;
 	}
 	codec->patch_ops = generic_hdmi_patch_ops;
+
+	if (codec->vendor_id == 0x80862807)
+		intel_haswell_allow_delay_resume(codec);
+
 	generic_hdmi_init_per_pins(codec);
 
 	init_channel_allocations();
-- 
1.7.10.4