From: Maxime Ripard <maxime.ripard@bootlin.com>
To: Georgii Staroselskii <georgii.staroselskii@emlid.com>
Cc: alsa-devel@alsa-project.org, dannym@scratchpost.org,
tiwai@suse.com, lgirdwood@gmail.com, wens@csie.org,
broonie@kernel.org, perex@perex.cz,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ASoC: sun4i-codec: fix first delay on Speaker
Date: Thu, 16 May 2019 22:12:56 +0200 [thread overview]
Message-ID: <20190516201256.te7ya3n7ugbfmzrw@flea> (raw)
In-Reply-To: <20190515152749.GA2241@softcrasher>
On Wed, May 15, 2019 at 06:27:49PM +0300, Georgii Staroselskii wrote:
> On Wed, May 15, 2019 at 03:58:13PM +0200, Maxime Ripard wrote:
> > > diff --git a/sound/soc/sunxi/sun4i-codec.c b/sound/soc/sunxi/sun4i-codec.c
> > > index 15d08e3..e0099519 100644
> > > --- a/sound/soc/sunxi/sun4i-codec.c
> > > +++ b/sound/soc/sunxi/sun4i-codec.c
> > > @@ -1329,6 +1329,15 @@ static int sun4i_codec_spk_event(struct snd_soc_dapm_widget *w,
> > > gpiod_set_value_cansleep(scodec->gpio_pa,
> > > !!SND_SOC_DAPM_EVENT_ON(event));
> > >
> > > + if (SND_SOC_DAPM_EVENT_ON(event)) {
> > > + /*
> > > + * 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);
> > > + }
> > > +
> >
> > Since this is an external amplifier, I guess they would have different
> > warm-up time depending on the exact part being used?
>
> I guess I might've used Speaker wrong and bumped into an existing
> issue. The issue first arose when I needed to connect a speaker and
> use a mute GPIO pin to toggle it. I bumped into the lag similar to
> the one that has been fixed in bf14da7. The word "amplifier" here in
> my comments might be wrong and misleding. Sorry for that. I just
> measured the latency on the speaker I'm using and it is well under
> 1ms so this is the Allwinner DAC that is pushing the data with a
> lag. Or some other thing, I'm not sure.
>
> I want to stress again that I might've experienced the issue because
> I was abusing "Speaker" routing. I basically just needed the analog
> audio stream and mute GPIO handling done automatically.
Ok. I guess the comment should just be reflecting that then.
Maxime
--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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next prev parent reply other threads:[~2019-05-16 20:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 12:58 [PATCH] ASoC: sun4i-codec: fix first delay on Speaker Georgii Staroselskii
2019-05-15 13:58 ` Maxime Ripard
2019-05-15 15:27 ` Georgii Staroselskii
2019-05-16 20:12 ` Maxime Ripard [this message]
2019-05-17 2:29 ` Chen-Yu Tsai
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