[v4,4/8] ASoC: sun8i-codec-analog: Add amplifier event to fix first delay
diff mbox

Message ID 20170202092422.5588-5-mylene.josserand@free-electrons.com
State New
Headers show

Commit Message

Mylene JOSSERAND Feb. 2, 2017, 9:24 a.m. UTC
When playing a sound for the first time, a short delay, where the audio
file is not played, can be noticed.
On a second play (right after), the sound is played correctly.
If we wait a short time (~5 sec which corresponds to the aplay
timeout), the delay is back.

This patch fixes it by using an event on headphone amplifier.
It allows to keep the amplifier enable while playing a sound.
A delay of 700ms allows to wait that the amplifier is powered-up
before playing the sound.

Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 sound/soc/sunxi/sun8i-codec-analog.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

Comments

Chen-Yu Tsai (Moxa) Feb. 10, 2017, 6:08 a.m. UTC | #1
On Thu, Feb 2, 2017 at 5:24 PM, Mylène Josserand
<mylene.josserand@free-electrons.com> wrote:
> When playing a sound for the first time, a short delay, where the audio
> file is not played, can be noticed.
> On a second play (right after), the sound is played correctly.
> If we wait a short time (~5 sec which corresponds to the aplay
> timeout), the delay is back.
>
> This patch fixes it by using an event on headphone amplifier.
> It allows to keep the amplifier enable while playing a sound.
> A delay of 700ms allows to wait that the amplifier is powered-up
> before playing the sound.
>
> Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

I get some static in my headphones in the time between when the
amplifier is enabled and when sound starts playing. Wonder if
this can be fixed in any way?

One solution that might work is to mute the headphone output
while the amp is being charged, by setting SUN8I_ADDA_HP_VOLC_HP_VOL
to 0, and then restoring the value once it is charged. In other
words, overriding the value for the duration of sun8i_headphone_amp_event.

Regards
ChenYu
Mark Brown Feb. 10, 2017, 12:01 p.m. UTC | #2
On Fri, Feb 10, 2017 at 02:08:54PM +0800, Chen-Yu Tsai wrote:

> One solution that might work is to mute the headphone output
> while the amp is being charged, by setting SUN8I_ADDA_HP_VOLC_HP_VOL
> to 0, and then restoring the value once it is charged. In other
> words, overriding the value for the duration of sun8i_headphone_amp_event.

This sounds like you want to make it an _AUTODISABLE control.

Patch
diff mbox

diff --git a/sound/soc/sunxi/sun8i-codec-analog.c b/sound/soc/sunxi/sun8i-codec-analog.c
index af02290ebe49..72331332b72e 100644
--- a/sound/soc/sunxi/sun8i-codec-analog.c
+++ b/sound/soc/sunxi/sun8i-codec-analog.c
@@ -398,11 +398,37 @@  static const struct snd_kcontrol_new sun8i_codec_hp_src[] = {
 		      sun8i_codec_hp_src_enum),
 };
 
+static int sun8i_headphone_amp_event(struct snd_soc_dapm_widget *w,
+				     struct snd_kcontrol *k, int event)
+{
+	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
+
+	if (SND_SOC_DAPM_EVENT_ON(event)) {
+		snd_soc_component_update_bits(component, SUN8I_ADDA_PAEN_HP_CTRL,
+					      BIT(SUN8I_ADDA_PAEN_HP_CTRL_HPPAEN),
+					      BIT(SUN8I_ADDA_PAEN_HP_CTRL_HPPAEN));
+		/*
+		 * Need a delay to have the amplifier up. 700ms seems the best
+		 * compromise between the time to let the amplifier up and the
+		 * time not to feel this delay while playing a sound.
+		 */
+		msleep(700);
+	} else if (SND_SOC_DAPM_EVENT_OFF(event)) {
+		snd_soc_component_update_bits(component, SUN8I_ADDA_PAEN_HP_CTRL,
+					      BIT(SUN8I_ADDA_PAEN_HP_CTRL_HPPAEN),
+					      0x0);
+	}
+
+	return 0;
+}
+
 static const struct snd_soc_dapm_widget sun8i_codec_headphone_widgets[] = {
 	SND_SOC_DAPM_MUX("Headphone Source Playback Route",
 			 SND_SOC_NOPM, 0, 0, sun8i_codec_hp_src),
-	SND_SOC_DAPM_OUT_DRV("Headphone Amp", SUN8I_ADDA_PAEN_HP_CTRL,
-			     SUN8I_ADDA_PAEN_HP_CTRL_HPPAEN, 0, NULL, 0),
+	SND_SOC_DAPM_OUT_DRV_E("Headphone Amp", SUN8I_ADDA_PAEN_HP_CTRL,
+			       SUN8I_ADDA_PAEN_HP_CTRL_HPPAEN, 0, NULL, 0,
+			       sun8i_headphone_amp_event,
+			       SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_PRE_PMD),
 	SND_SOC_DAPM_SUPPLY("HPCOM Protection", SUN8I_ADDA_PAEN_HP_CTRL,
 			    SUN8I_ADDA_PAEN_HP_CTRL_COMPTEN, 0, NULL, 0),
 	SND_SOC_DAPM_REG(snd_soc_dapm_supply, "HPCOM", SUN8I_ADDA_PAEN_HP_CTRL,