[alsa-devel] [PATCH 3/3] ASoC: hdac_hdmi : Ensuring proper setting of output widget power state

[Takashi Iwai]

On Tue, 23 Jan 2018 18:30:53 +0100,
<abhijeet.kumar at intel.com> wrote:
> 
> From: Abhijeet Kumar <abhijeet.kumar at intel.com>
> 
> In usecases like hot plug-unplug DP panel or modeset during a playback,
> sometimes we observe no audio after codec resets. During no audio
> condition, we have noticed that the power state of the pin or the
> connector is D3. Optimizing the way we set the power mitigates the
> issue. With this changes the verb is sent to set the power state and
> waits until actual state reaches target state. Thus ensuring power state
> is set.
> 
> Signed-off-by: Abhijeet Kumar <abhijeet.kumar at intel.com>

I applied the patches 1 and 2 to topic/hda-sync-power branch.  It's
based on 4.16-rc1.

Mark, could you pull that into your intel branch and apply this fix?


thanks,

Takashi


> ---
>  sound/soc/codecs/hdac_hdmi.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/soc/codecs/hdac_hdmi.c b/sound/soc/codecs/hdac_hdmi.c
> index f3b4f4dfae6a..4dc9b9b71db9 100644
> --- a/sound/soc/codecs/hdac_hdmi.c
> +++ b/sound/soc/codecs/hdac_hdmi.c
> @@ -716,10 +716,20 @@ static struct hdac_hdmi_pcm *hdac_hdmi_get_pcm(struct hdac_ext_device *edev,
>  static void hdac_hdmi_set_power_state(struct hdac_ext_device *edev,
>  			     hda_nid_t nid, unsigned int pwr_state)
>  {
> +	int count;
> +	unsigned int state;
>  	if (get_wcaps(&edev->hdac, nid) & AC_WCAP_POWER) {
> -		if (!snd_hdac_check_power_state(&edev->hdac, nid, pwr_state))
> -			snd_hdac_codec_write(&edev->hdac, nid, 0,
> -				AC_VERB_SET_POWER_STATE, pwr_state);
> +		if (!snd_hdac_check_power_state(&edev->hdac, nid, pwr_state)) {
> +			for (count = 0; count < 10; count++) {
> +				snd_hdac_codec_read(&edev->hdac, nid, 0,
> +						AC_VERB_SET_POWER_STATE,
> +						pwr_state);
> +				state = snd_hdac_sync_power_state(&edev->hdac,
> +						 nid, pwr_state);
> +				if (!(state & AC_PWRST_ERROR))
> +					break;
> +			}
> +		}
>  	}
>  }
>  
> -- 
> 1.9.1
> 
>