设置card->power_state

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snd_soc_suspend
	snd_power_change_state(card->snd_card, SNDRV_CTL_POWER_D3hot);
		card->power_state = state;

snd_soc_dapm_dac||snd_soc_dapm_aif_in||snd_soc_dapm_input||snd_soc_dapm_vmid||snd_soc_dapm_mic||snd_soc_dapm_line都属于input_ep

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static int (struct snd_soc_dapm_widget *widget) { switch (widget->id) { case snd_soc_dapm_dac: case snd_soc_dapm_aif_in: if (widget->active) // 声卡正常工作的情况下return 1，所以说snd_soc_dapm_dac||snd_soc_dapm_aif_in也是一类input_ep return snd_soc_dapm_suspend_check(widget); } // 如果是snd_soc_dapm_input||snd_soc_dapm_vmid||snd_soc_dapm_mic||snd_soc_dapm_line且没有suspend，则return 1 if (widget->connected) { /* connected pin ? */ if (widget->id == snd_soc_dapm_input && !widget->ext) // 没有suspend则return 1 // SNDRV_CTL_POWER_D3已经是off了 return snd_soc_dapm_suspend_check(widget); level = snd_power_get_state(widget->dapm->card->snd_card); return card->power_state; default: return 1; } // 递归往前搜寻 // widget找到path，最终到达path->source list_for_each_entry(path, &widget->sources, list_sink) { if (path->walked) continue; if (path->source && path->connect) { path->walked = 1; con += is_connected_input_ep(path->source); } } }

snd_soc_dapm_adc||snd_soc_dapm_aif_out||snd_soc_dapm_output||snd_soc_dapm_hp||snd_soc_dapm_spk||snd_soc_dapm_line都属于output_ep

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static int is_connected_output_ep(struct snd_soc_dapm_widget *widget) { // snd_soc_dapm_adc||snd_soc_dapm_aif_out switch (widget->id) { case snd_soc_dapm_adc: case snd_soc_dapm_aif_out: if (widget->active) return snd_soc_dapm_suspend_check(widget); // 声卡正常工作的情况下return 1，所以说snd_soc_dapm_adc||snd_soc_dapm_aif_out也是一类output_ep int level = snd_power_get_state(widget->dapm->card->snd_card); switch (level) { case SNDRV_CTL_POWER_D3hot: case SNDRV_CTL_POWER_D3cold: return widget->ignore_suspend; default: return 1; } // snd_soc_dapm_output||snd_soc_dapm_hp||snd_soc_dapm_spk||snd_soc_dapm_line if (widget->connected) { /* connected pin ? */ if (widget->id == snd_soc_dapm_output && !widget->ext) return snd_soc_dapm_suspend_check(widget); /* connected jack or spk ? */ if (widget->id == snd_soc_dapm_hp || widget->id == snd_soc_dapm_spk || (widget->id == snd_soc_dapm_line && !list_empty(&widget->sources))) return snd_soc_dapm_suspend_check(widget); } // 往后递归找到output_ep list_for_each_entry(path, &widget->sinks, list_source) { if (path->walked) continue; if (path->sink && path->connect) { path->walked = 1; con += is_connected_output_ep(path->sink); } } }