Re: [alsa-devel] [PATCH v4] ASoC: ak4613: call dummy write for PW_MGMT1/3 when Playback

5 Dec 2017


      Hi Takashi, again
...
...
+static void ak4613_dummy_write(struct work_struct *work)
+{

struct ak4613_priv *priv = container_of(work,
				struct ak4613_priv,


				dummy_write_work);


struct snd_soc_component *component = priv->component;
unsigned int mgmt1;
unsigned int mgmt3;

/* wait 5 LR clocks */
udelay(5000000 / priv->rate);

snd_soc_component_read(component, PW_MGMT1, &mgmt1);
snd_soc_component_read(component, PW_MGMT3, &mgmt3);

snd_soc_component_write(component, PW_MGMT1, mgmt1);
snd_soc_component_write(component, PW_MGMT3, mgmt3);

+}
In my understanding, it's better to have care of kernel preemption in
this case because data transmission is already activated and these
should be executed as quick as possible to prevent much presentation
loss.
To avoid v6 patch, I want to know more clearly.
Do you mean it needs spin lock ?
If so lock in trigger, and unlock here ?
Or lock/unlock on each ?
Best regards
---
Kuninori Morimoto