audio: mic_privacy: Fix feature functionality after D3 resume

When resuming from D3 state, the microphone privacy feature wasn't
properly restored, causing two critical issues:

1. The system didn't respond to privacy button inputs after D3
   transitions
2. A short fade-out effect appeared in audio when privacy was enabled,
   causing test failures that expected complete silence

This patch provides a comprehensive solution by:
- Adding mic_privacy_manager_init() to resume_dais() to ensure proper
  re-initialization of the microphone privacy subsystem after D3
- Implementing mic_privacy_get_mic_disable_status() to correctly
  retrieve the current microphone disable status
- Storing the mic_disable_status before entering D3 and comparing it
  after resume to detect changes during low power state
- Enhancing mic_privacy_enable_dmic_irq() to immediately check for IRQ
  status after D3 transitions to catch events that occurred during
  suspended state
- Explicitly resetting fade parameters (fade_in_out_bytes, gain
  parameters) to ensure immediate silence without fade artifacts when
  privacy is enabled
- Adding proper error handling and validation to ensure the mic_priv
  structure is valid before access

With these changes, the microphone privacy feature works correctly
through power state transitions and properly mutes audio without fade
artifacts when privacy is enabled after D3 resume.

Signed-off-by: Tomasz Leman <tomasz.m.leman@intel.com>
(cherry picked from commit aea8101)
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Author: tmleman

src/audio/mic_privacy_manager/mic_privacy_manager_intel.c

@@ -62,11 +62,29 @@ static void enable_fw_managed_irq(bool enable_irq)
 
 void mic_privacy_enable_dmic_irq(bool enable_irq)
 {
+	/* Only proceed if we have a valid device and API */
+	if (!mic_priv_dev || !mic_privacy_api) {
+		LOG_ERR("mic_privacy device or API not initialized");
+		return;
+	}
+
 	if (mic_privacy_api->get_policy() == MIC_PRIVACY_HW_MANAGED) {
-		if (enable_irq)
+		if (enable_irq) {
 			mic_privacy_api->enable_dmic_irq(true, handle_dmic_irq);
-		else
+
+			/* Check current status immediately to handle any transitions during D3 */
+			if (mic_privacy_api->get_dmic_irq_status()) {
+				struct mic_privacy_settings settings;
+				uint32_t mic_disable_status =
+					mic_privacy_api->get_dmic_mic_disable_status();
+
+				mic_privacy_fill_settings(&settings, mic_disable_status);
+				mic_privacy_propagate_settings(&settings);
+				mic_privacy_api->clear_dmic_irq_status();
+			}
+		} else {
 			mic_privacy_api->enable_dmic_irq(false, NULL);
+		}
 	}
 }
 
@@ -235,3 +253,17 @@ void mic_privacy_process(struct comp_dev *dev, struct mic_privacy_data *mic_priv
 		break;
 	}
 }
+
+uint32_t mic_privacy_get_mic_disable_status(void)
+{
+	if (!mic_priv_dev) {
+		LOG_ERR("mic_privacy device not initialized");
+		return 0;
+	}
+
+	mic_privacy_api = (struct mic_privacy_api_funcs *)mic_priv_dev->api;
+	if (mic_privacy_api->get_policy() == MIC_PRIVACY_FW_MANAGED)
+		return mic_privacy_api->get_fw_managed_mic_disable_status();
+
+	return mic_privacy_api->get_dmic_mic_disable_status();
+}

src/include/sof/audio/mic_privacy_manager.h

@@ -51,6 +51,7 @@ uint32_t mic_privacy_get_policy_register(void);
 void mic_privacy_propagate_settings(struct mic_privacy_settings *settings);
 uint32_t mic_privacy_get_dma_zeroing_wait_time(void);
 uint32_t mic_privacy_get_privacy_mask(void);
+uint32_t mic_privacy_get_mic_disable_status(void);
 void mic_privacy_enable_dmic_irq(bool enable_irq);
 void mic_privacy_fill_settings(struct mic_privacy_settings *settings, uint32_t mic_disable_status);
 void mic_privacy_set_gtw_mic_state(struct mic_privacy_data *mic_priv_data,

zephyr/lib/cpu.c

@@ -11,6 +11,12 @@
  */
 
 #include <sof/audio/component.h>
+#if CONFIG_INTEL_ADSP_MIC_PRIVACY
+#include <sof/audio/mic_privacy_manager.h>
+#ifdef CONFIG_ADSP_IMR_CONTEXT_SAVE
+static uint32_t mic_disable_status;
+#endif /* CONFIG_ADSP_IMR_CONTEXT_SAVE */
+#endif /* CONFIG_INTEL_ADSP_MIC_PRIVACY */
 #include <sof/init.h>
 #include <sof/lib/cpu.h>
 #include <sof/lib/pm_runtime.h>
@@ -64,6 +70,7 @@ extern void *global_imr_ram_storage;
  * data integrity across D3 transitions, which is critical for SOF's operation
  * and currently outside the scope of Zephyr's device-level PM capabilities.
  */
+
 static void suspend_dais(void)
 {
 	struct ipc_comp_dev *icd;
@@ -79,6 +86,10 @@ static void suspend_dais(void)
 
 		mod = comp_mod(icd->cd);
 		cd = module_get_private_data(mod);
+#if CONFIG_INTEL_ADSP_MIC_PRIVACY
+		if (cd->mic_priv)
+			mic_disable_status = mic_privacy_get_mic_disable_status();
+#endif
 		dd = cd->dd[0];
 		if (dai_remove(dd->dai->dev) < 0) {
 			tr_err(&zephyr_tr, "DAI suspend failed, type %d index %d",
@@ -95,6 +106,11 @@ static void resume_dais(void)
 	struct copier_data *cd;
 	struct dai_data *dd;
 
+#if CONFIG_INTEL_ADSP_MIC_PRIVACY
+	/* Re-initialize mic privacy manager first to ensure proper state before DAI resume */
+	mic_privacy_manager_init();
+#endif
+
 	list_for_item(clist, &ipc_get()->comp_list) {
 		icd = container_of(clist, struct ipc_comp_dev, list);
 		if (icd->type != COMP_TYPE_COMPONENT || dev_comp_type(icd->cd) != SOF_COMP_DAI)
@@ -107,6 +123,29 @@ static void resume_dais(void)
 			tr_err(&zephyr_tr, "DAI resume failed, type %d index %d",
 			       dd->dai->type, dd->dai->index);
 		}
+
+#if CONFIG_INTEL_ADSP_MIC_PRIVACY
+		if (cd->mic_priv) {
+			uint32_t current_mic_status = mic_privacy_get_mic_disable_status();
+
+			if (mic_disable_status != current_mic_status) {
+				tr_dbg(&zephyr_tr, "MIC privacy settings cheange after D3");
+				struct mic_privacy_settings settings;
+
+				/* Update privacy settings based on new state */
+				mic_privacy_fill_settings(&settings, current_mic_status);
+				mic_privacy_propagate_settings(&settings);
+				/* Ensure we're starting from a clean state with no fade effects */
+				if (cd->mic_priv->mic_privacy_state) {
+					/* Force immediate mute without fade effect */
+					cd->mic_priv->mic_privacy_state = MIC_PRIV_MUTED;
+					cd->mic_priv->fade_in_out_bytes = 0;
+					cd->mic_priv->mic_priv_gain_params.gain_env = 0;
+					cd->mic_priv->mic_priv_gain_params.fade_in_sg_count = 0;
+				}
+			}
+		}
+#endif
 	}
 }
 #endif /* CONFIG_ADSP_IMR_CONTEXT_SAVE */