[PATCH 1/2] ALSA: hda - check supported power states

[PATCH 1/2] ALSA: hda - check supported power states

[Wang Xingchao]

Add function to check whether power states supported by specific
codec node.

Signed-off-by: Wang Xingchao <xingchao.wang@intel.com>
---
 sound/pci/hda/hda_codec.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 41ca803..b89c8ec 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3505,6 +3505,22 @@ void snd_hda_codec_set_power_to_all(struct hda_codec *codec, hda_nid_t fg,
 EXPORT_SYMBOL_HDA(snd_hda_codec_set_power_to_all);
 
 /*
+ *  supported power states check
+ */
+static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec, hda_nid_t fg,
+				unsigned int power_state)
+{
+	int sup = snd_hda_param_read(codec, fg, AC_PAR_POWER_STATE);
+
+	if (sup < 0)
+		return false;
+	if (sup & power_state)
+		return true;
+	else
+		return false;
+}
+
+/*
  * set power state of the codec
  */
 static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
-- 
1.7.9.5

[PATCH 2/2] ALSA: hda - reduce msleep time if EPSS power states supported

[Wang Xingchao]

if EPSS supported, transition from D3 state to D0 state in less
than 10ms

Signed-off-by: Wang Xingchao <xingchao.wang@intel.com>
---
 sound/pci/hda/hda_codec.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index b89c8ec..5298ba1 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3526,14 +3526,18 @@ static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec, hda_nid_t fg
 static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
 				unsigned int power_state)
 {
+	bool epss;
 	if (codec->patch_ops.set_power_state) {
 		codec->patch_ops.set_power_state(codec, fg, power_state);
 		return;
 	}
 
+	epss = snd_hda_codec_get_supported_ps(codec, fg, AC_PWRST_EPSS);
 	/* this delay seems necessary to avoid click noise at power-down */
-	if (power_state == AC_PWRST_D3)
+	if ((power_state == AC_PWRST_D3) && !epss)
 		msleep(100);
+	else
+		msleep(10);
 	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, true);
-- 
1.7.9.5

Re: [PATCH 2/2] ALSA: hda - reduce msleep time if EPSS power states supported

[David Henningsson]

On 06/06/2012 04:02 PM, Wang Xingchao wrote:
> if EPSS supported, transition from D3 state to D0 state in less
> than 10ms
>
> Signed-off-by: Wang Xingchao<xingchao.wang@intel.com>
> ---
>   sound/pci/hda/hda_codec.c |    6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> index b89c8ec..5298ba1 100644
> --- a/sound/pci/hda/hda_codec.c
> +++ b/sound/pci/hda/hda_codec.c
> @@ -3526,14 +3526,18 @@ static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec, hda_nid_t fg
>   static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
>   				unsigned int power_state)
>   {
> +	bool epss;
>   	if (codec->patch_ops.set_power_state) {
>   		codec->patch_ops.set_power_state(codec, fg, power_state);
>   		return;
>   	}
>
> +	epss = snd_hda_codec_get_supported_ps(codec, fg, AC_PWRST_EPSS);
>   	/* this delay seems necessary to avoid click noise at power-down */
> -	if (power_state == AC_PWRST_D3)
> +	if ((power_state == AC_PWRST_D3)&&  !epss)
>   		msleep(100);
> +	else
> +		msleep(10);

Hi Wang,

You seem to have increased the delay from 0 to 10 ms on all cases when 
power_state != AC_PWRST_D3, is this intentional?

Or did you mean to write like this:

	if (power_state == AC_PWRST_D3) {
		bool epss = snd_hda_codec_get_supported_ps(codec, fg, AC_PWRST_EPSS);
		msleep(epss ? 10 : 100);
	}


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic

Re: [PATCH 2/2] ALSA: hda - reduce msleep time if EPSS power states supported

[Wang Xingchao]

Hi David,


2012/6/7 David Henningsson <david.henningsson@canonical.com>:
> On 06/06/2012 04:02 PM, Wang Xingchao wrote:
>>
>> if EPSS supported, transition from D3 state to D0 state in less
>> than 10ms
>>
>> Signed-off-by: Wang Xingchao<xingchao.wang@intel.com>
>> ---
>>  sound/pci/hda/hda_codec.c |    6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
>> index b89c8ec..5298ba1 100644
>> --- a/sound/pci/hda/hda_codec.c
>> +++ b/sound/pci/hda/hda_codec.c
>> @@ -3526,14 +3526,18 @@ static bool snd_hda_codec_get_supported_ps(struct
>> hda_codec *codec, hda_nid_t fg
>>  static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
>>                                unsigned int power_state)
>>  {
>> +       bool epss;
>>        if (codec->patch_ops.set_power_state) {
>>                codec->patch_ops.set_power_state(codec, fg, power_state);
>>                return;
>>        }
>>
>> +       epss = snd_hda_codec_get_supported_ps(codec, fg, AC_PWRST_EPSS);
>>        /* this delay seems necessary to avoid click noise at power-down */
>> -       if (power_state == AC_PWRST_D3)
>> +       if ((power_state == AC_PWRST_D3)&&  !epss)
>>
>>                msleep(100);
>> +       else
>> +               msleep(10);
>
>
> Hi Wang,
>
> You seem to have increased the delay from 0 to 10 ms on all cases when
> power_state != AC_PWRST_D3, is this intentional?

Thanks for clarification, it's a mistake here. Only transition from D0
to D3 need the delay to avoid click noise, there's no limitation
during power up.
i will update the patch based on your suggestion.

thanks
--xingchao

>
> Or did you mean to write like this:
>
>        if (power_state == AC_PWRST_D3) {
>                bool epss = snd_hda_codec_get_supported_ps(codec, fg,
> AC_PWRST_EPSS);
>                msleep(epss ? 10 : 100);
>        }
>
>
> --
> David Henningsson, Canonical Ltd.
> https://launchpad.net/~diwic

Re: [PATCH 1/2] ALSA: hda - check supported power states

[Takashi Iwai]

At Wed,  6 Jun 2012 22:02:48 +0800,
Wang Xingchao wrote:
> 
> Add function to check whether power states supported by specific
> codec node.
> 
> Signed-off-by: Wang Xingchao <xingchao.wang@intel.com>

Applied together with v2 patch.  Thanks.


Takashi

> ---
>  sound/pci/hda/hda_codec.c |   16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> index 41ca803..b89c8ec 100644
> --- a/sound/pci/hda/hda_codec.c
> +++ b/sound/pci/hda/hda_codec.c
> @@ -3505,6 +3505,22 @@ void snd_hda_codec_set_power_to_all(struct hda_codec *codec, hda_nid_t fg,
>  EXPORT_SYMBOL_HDA(snd_hda_codec_set_power_to_all);
>  
>  /*
> + *  supported power states check
> + */
> +static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec, hda_nid_t fg,
> +				unsigned int power_state)
> +{
> +	int sup = snd_hda_param_read(codec, fg, AC_PAR_POWER_STATE);
> +
> +	if (sup < 0)
> +		return false;
> +	if (sup & power_state)
> +		return true;
> +	else
> +		return false;
> +}
> +
> +/*
>   * set power state of the codec
>   */
>  static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
> -- 
> 1.7.9.5
>