[NOT FOR UPSTREAM] ASoC: SOF: Don't suspend in IPC4 mode

Currently we are not able to wake DSP up once it is suspended in IPC4
mode. This patch uses pm_runtime_get() to prevent DSP from entering
suspend. This should be revert once PM is supported in IPC4 mode.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>

sound/soc/sof/ipc4.c

@@ -231,6 +231,12 @@ int sof_ipc4_init_msg_memory(struct snd_sof_dev *sdev)
 	if (!msg->reply_data)
 		return -ENOMEM;
 
+	/*
+	 * TODO: Currently we are not able to wake DSP up once it is suspended.
+	 * Calling pm_runtime_get_sync() here to prevent it from entering
+	 * suspend. This should be removed once power management is implemented
+	 */
+	pm_runtime_get_sync(sdev->dev);
 	return 0;
 }
 EXPORT_SYMBOL(sof_ipc4_init_msg_memory);

sound/soc/sof/loader.c

@@ -863,5 +863,15 @@ void snd_sof_fw_unload(struct snd_sof_dev *sdev)
 	/* TODO: support module unloading at runtime */
 	release_firmware(sdev->pdata->fw);
 	sdev->pdata->fw = NULL;
+
+	/*
+	 * TODO: Currently we are not able to wake DSP up once it is suspended.
+	 * Therefore pm_runtime_get_sync() is called by sof_ipc4_init_msg_memory()
+	 * to prevent DSP from entering suspend. Call pm_runtime_put_noidle()
+	 * here to balance it.
+	 */
+	if (sof_get_abi_major(sdev) >= 4)
+		pm_runtime_put_noidle(sdev->dev);
+
 }
 EXPORT_SYMBOL(snd_sof_fw_unload);