[alsa-devel] [PATCH] SoC: simple-card-utils: set 0Hz to sysclk when shutdown
This patch set 0Hz to sysclk when shutdown the card.
Some codecs set rate constraints that derives from sysclk. This mechanism works correctly if machine drivers give fixed frequency.
But simple-audio and audio-graph card set variable clock rate if 'mclk-fs' property exists. In this case, rate constraints will go bad scenario. For example a codec accepts three limited rates (mclk / 256, mclk / 384, mclk / 512).
Bad scenario as follows (mclk-fs = 256): - Initialize sysclk by correct value (Ex. 12.288MHz) - Codec set constraints of PCM rate by sysclk 48kHz (1/256), 32kHz (1/384), 24kHz (1/512) - Play 48kHz sound, it's acceptable - Sysclk is not changed
- Play 32kHz sound, it's acceptable - Set sysclk to 8.192MHz (= fs * mclk-fs = 32k * 256) - Codec set constraints of PCM rate by sysclk 32kHz (1/256), 21.33kHz (1/384), 16kHz (1/512)
- Play 48kHz again, but it's NOT acceptable because constraints do not allow 48kHz
So codecs treat 0Hz sysclk as signal of applying no constraints to avoid this problem.
Signed-off-by: Katsuhiro Suzuki katsuhiro@katsuster.net --- sound/soc/generic/simple-card-utils.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c index 556b1a789629..9b794775df53 100644 --- a/sound/soc/generic/simple-card-utils.c +++ b/sound/soc/generic/simple-card-utils.c @@ -213,10 +213,17 @@ EXPORT_SYMBOL_GPL(asoc_simple_startup); void asoc_simple_shutdown(struct snd_pcm_substream *substream) { struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_dai *codec_dai = rtd->codec_dai; + struct snd_soc_dai *cpu_dai = rtd->cpu_dai; struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(rtd->card); struct simple_dai_props *dai_props = simple_priv_to_props(priv, rtd->num);
+ if (dai_props->mclk_fs) { + snd_soc_dai_set_sysclk(codec_dai, 0, 0, SND_SOC_CLOCK_IN); + snd_soc_dai_set_sysclk(cpu_dai, 0, 0, SND_SOC_CLOCK_OUT); + } + asoc_simple_clk_disable(dai_props->cpu_dai);
asoc_simple_clk_disable(dai_props->codec_dai);
Hi Katsuhiro
This patch set 0Hz to sysclk when shutdown the card.
Some codecs set rate constraints that derives from sysclk. This mechanism works correctly if machine drivers give fixed frequency.
But simple-audio and audio-graph card set variable clock rate if 'mclk-fs' property exists. In this case, rate constraints will go bad scenario. For example a codec accepts three limited rates (mclk / 256, mclk / 384, mclk / 512).
Bad scenario as follows (mclk-fs = 256):
Initialize sysclk by correct value (Ex. 12.288MHz)
- Codec set constraints of PCM rate by sysclk 48kHz (1/256), 32kHz (1/384), 24kHz (1/512)
Play 48kHz sound, it's acceptable
Sysclk is not changed
Play 32kHz sound, it's acceptable
Set sysclk to 8.192MHz (= fs * mclk-fs = 32k * 256)
- Codec set constraints of PCM rate by sysclk 32kHz (1/256), 21.33kHz (1/384), 16kHz (1/512)
Play 48kHz again, but it's NOT acceptable because constraints do not allow 48kHz
So codecs treat 0Hz sysclk as signal of applying no constraints to avoid this problem.
Signed-off-by: Katsuhiro Suzuki katsuhiro@katsuster.net
I'm not 100% understand your issue. .hw_params (= set mclk/sysclk) is not called in bad case ?? Or it is called but Codec driver ignores it somehow ??
Thank you for your help !! Best regards --- Kuninori Morimoto
On 2019/09/09 9:31, Kuninori Morimoto wrote:
Hi Katsuhiro
This patch set 0Hz to sysclk when shutdown the card.
Some codecs set rate constraints that derives from sysclk. This mechanism works correctly if machine drivers give fixed frequency.
But simple-audio and audio-graph card set variable clock rate if 'mclk-fs' property exists. In this case, rate constraints will go bad scenario. For example a codec accepts three limited rates (mclk / 256, mclk / 384, mclk / 512).
Bad scenario as follows (mclk-fs = 256): - Initialize sysclk by correct value (Ex. 12.288MHz) - Codec set constraints of PCM rate by sysclk 48kHz (1/256), 32kHz (1/384), 24kHz (1/512) - Play 48kHz sound, it's acceptable - Sysclk is not changed
- Play 32kHz sound, it's acceptable - Set sysclk to 8.192MHz (= fs * mclk-fs = 32k * 256) - Codec set constraints of PCM rate by sysclk 32kHz (1/256), 21.33kHz (1/384), 16kHz (1/512) - Play 48kHz again, but it's NOT acceptable because constraints do not allow 48kHzSo codecs treat 0Hz sysclk as signal of applying no constraints to avoid this problem.
Signed-off-by: Katsuhiro Suzuki katsuhiro@katsuster.net
I'm not 100% understand your issue. .hw_params (= set mclk/sysclk) is not called in bad case ?? Or it is called but Codec driver ignores it somehow ??
Ah, sorry for confusing. It's not either. hw_params() of machine driver has been called even if constraints don't have a requested PCM rate. But it's not expected.
For example, if constraints are 32k, 21.33k, 16k, hw_params() will be called with 32k when an user requests to play 48k sounds.
Thank you for your help !! Best regards
Kuninori Morimoto
Best Regards, Katsuhiro Suzuki
Hi Katsuhiro
Bad scenario as follows (mclk-fs = 256): - Initialize sysclk by correct value (Ex. 12.288MHz) - Codec set constraints of PCM rate by sysclk 48kHz (1/256), 32kHz (1/384), 24kHz (1/512) - Play 48kHz sound, it's acceptable - Sysclk is not changed
- Play 32kHz sound, it's acceptable - Set sysclk to 8.192MHz (= fs * mclk-fs = 32k * 256) - Codec set constraints of PCM rate by sysclk 32kHz (1/256), 21.33kHz (1/384), 16kHz (1/512) - Play 48kHz again, but it's NOT acceptable because constraints do not allow 48kHz
(snip)
Ah, sorry for confusing. It's not either. hw_params() of machine driver has been called even if constraints don't have a requested PCM rate. But it's not expected.
For example, if constraints are 32k, 21.33k, 16k, hw_params() will be called with 32k when an user requests to play 48k sounds.
Oh, I see. Thank you for explaining.
Thank you for your help !! Best regards --- Kuninori Morimoto
The patch
SoC: simple-card-utils: set 0Hz to sysclk when shutdown
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.4
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From 2458adb8f92ad4d07ef7ab27c5bafa1d3f4678d6 Mon Sep 17 00:00:00 2001
From: Katsuhiro Suzuki katsuhiro@katsuster.net Date: Sun, 8 Sep 2019 02:45:01 +0900 Subject: [PATCH] SoC: simple-card-utils: set 0Hz to sysclk when shutdown
This patch set 0Hz to sysclk when shutdown the card.
Some codecs set rate constraints that derives from sysclk. This mechanism works correctly if machine drivers give fixed frequency.
But simple-audio and audio-graph card set variable clock rate if 'mclk-fs' property exists. In this case, rate constraints will go bad scenario. For example a codec accepts three limited rates (mclk / 256, mclk / 384, mclk / 512).
Bad scenario as follows (mclk-fs = 256): - Initialize sysclk by correct value (Ex. 12.288MHz) - Codec set constraints of PCM rate by sysclk 48kHz (1/256), 32kHz (1/384), 24kHz (1/512) - Play 48kHz sound, it's acceptable - Sysclk is not changed
- Play 32kHz sound, it's acceptable - Set sysclk to 8.192MHz (= fs * mclk-fs = 32k * 256) - Codec set constraints of PCM rate by sysclk 32kHz (1/256), 21.33kHz (1/384), 16kHz (1/512)
- Play 48kHz again, but it's NOT acceptable because constraints do not allow 48kHz
So codecs treat 0Hz sysclk as signal of applying no constraints to avoid this problem.
Signed-off-by: Katsuhiro Suzuki katsuhiro@katsuster.net Link: https://lore.kernel.org/r/20190907174501.19833-1-katsuhiro@katsuster.net Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/generic/simple-card-utils.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c index 556b1a789629..9b794775df53 100644 --- a/sound/soc/generic/simple-card-utils.c +++ b/sound/soc/generic/simple-card-utils.c @@ -213,10 +213,17 @@ EXPORT_SYMBOL_GPL(asoc_simple_startup); void asoc_simple_shutdown(struct snd_pcm_substream *substream) { struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_dai *codec_dai = rtd->codec_dai; + struct snd_soc_dai *cpu_dai = rtd->cpu_dai; struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(rtd->card); struct simple_dai_props *dai_props = simple_priv_to_props(priv, rtd->num);
+ if (dai_props->mclk_fs) { + snd_soc_dai_set_sysclk(codec_dai, 0, 0, SND_SOC_CLOCK_IN); + snd_soc_dai_set_sysclk(cpu_dai, 0, 0, SND_SOC_CLOCK_OUT); + } + asoc_simple_clk_disable(dai_props->cpu_dai);
asoc_simple_clk_disable(dai_props->codec_dai);
participants (3)
-
Katsuhiro Suzuki -
Kuninori Morimoto -
Mark Brown