ASoC: SOF: Intel: fix resume from hibernate

Merge series from Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>:

The enablement of IMR-based DSP boot helped reduce resume latency, but
unfortunately the context is not saved in S4 and S5 which leads to
multiple reports of boot failures.

This patchset forces a full firmware reload/reboot when resuming from
S4/S5 and restores functionality.

sound/soc/sof/intel/hda-loader.c

@@ -389,7 +389,8 @@ int hda_dsp_cl_boot_firmware(struct snd_sof_dev *sdev)
 	struct snd_dma_buffer dmab;
 	int ret, ret1, i;
 
-	if (hda->imrboot_supported && !sdev->first_boot) {
+	if (sdev->system_suspend_target < SOF_SUSPEND_S4 &&
+	    hda->imrboot_supported && !sdev->first_boot) {
 		dev_dbg(sdev->dev, "IMR restore supported, booting from IMR directly\n");
 		hda->boot_iteration = 0;
 		ret = hda_dsp_boot_imr(sdev);

sound/soc/sof/pm.c

@@ -23,6 +23,9 @@ static u32 snd_sof_dsp_power_target(struct snd_sof_dev *sdev)
 	u32 target_dsp_state;
 
 	switch (sdev->system_suspend_target) {
+	case SOF_SUSPEND_S5:
+	case SOF_SUSPEND_S4:
+		/* DSP should be in D3 if the system is suspending to S3+ */
 	case SOF_SUSPEND_S3:
 		/* DSP should be in D3 if the system is suspending to S3 */
 		target_dsp_state = SOF_DSP_PM_D3;
@@ -335,8 +338,24 @@ int snd_sof_prepare(struct device *dev)
 		return 0;
 
 #if defined(CONFIG_ACPI)
-	if (acpi_target_system_state() == ACPI_STATE_S0)
+	switch (acpi_target_system_state()) {
+	case ACPI_STATE_S0:
 		sdev->system_suspend_target = SOF_SUSPEND_S0IX;
+		break;
+	case ACPI_STATE_S1:
+	case ACPI_STATE_S2:
+	case ACPI_STATE_S3:
+		sdev->system_suspend_target = SOF_SUSPEND_S3;
+		break;
+	case ACPI_STATE_S4:
+		sdev->system_suspend_target = SOF_SUSPEND_S4;
+		break;
+	case ACPI_STATE_S5:
+		sdev->system_suspend_target = SOF_SUSPEND_S5;
+		break;
+	default:
+		break;
+	}
 #endif
 
 	return 0;

sound/soc/sof/sof-priv.h

@@ -85,6 +85,8 @@ enum sof_system_suspend_state {
 	SOF_SUSPEND_NONE = 0,
 	SOF_SUSPEND_S0IX,
 	SOF_SUSPEND_S3,
+	SOF_SUSPEND_S4,
+	SOF_SUSPEND_S5,
 };
 
 enum sof_dfsentry_type {