Re: [PATCH 12/14] ASoC: Intel: avs: Power management

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 4/26/22 12:23, Cezary Rojewski wrote:
> To preserve power during sleep operations, handle suspend (S3),
> hibernation (S4) and runtime (RTD3) transitions. As flow for all of
> is shared, define common handlers to reduce code size.
> 
> Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
> Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
> ---
>  sound/soc/intel/avs/core.c | 125 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 125 insertions(+)
> 
> diff --git a/sound/soc/intel/avs/core.c b/sound/soc/intel/avs/core.c
> index 93180c22032d..c2f8fb87cfc2 100644
> --- a/sound/soc/intel/avs/core.c
> +++ b/sound/soc/intel/avs/core.c
> @@ -536,6 +536,128 @@ static void avs_pci_remove(struct pci_dev *pci)
>  	pm_runtime_get_noresume(&pci->dev);
>  }
>  
> +static int __maybe_unused avs_suspend_common(struct avs_dev *adev, bool low_power)

low_power is not used so....

> +{
> +	struct hdac_bus *bus = &adev->base.core;
> +	int ret;
> +
> +	flush_work(&adev->probe_work);
> +
> +	snd_hdac_ext_bus_link_power_down_all(bus);
> +
> +	ret = avs_ipc_set_dx(adev, AVS_MAIN_CORE_MASK, false);
> +	/*
> +	 * pm_runtime is blocked on DSP failure but system-wide suspend is not.
> +	 * Do not block entire system from suspending if that's the case.
> +	 */
> +	if (ret && ret != -EPERM) {
> +		dev_err(adev->dev, "set dx failed: %d\n", ret);
> +		return AVS_IPC_RET(ret);
> +	}
> +
> +	avs_dsp_op(adev, int_control, false);
> +	snd_hdac_ext_bus_ppcap_int_enable(bus, false);
> +
> +	ret = avs_dsp_core_disable(adev, AVS_MAIN_CORE_MASK);
> +	if (ret < 0) {
> +		dev_err(adev->dev, "core_mask %ld disable failed: %d\n", AVS_MAIN_CORE_MASK, ret);
> +		return ret;
> +	}
> +
> +	snd_hdac_ext_bus_ppcap_enable(bus, false);
> +	/* disable LP SRAM retention */
> +	avs_hda_power_gating_enable(adev, false);
> +	snd_hdac_bus_stop_chip(bus);
> +	/* disable CG when putting controller to reset */
> +	avs_hdac_clock_gating_enable(bus, false);
> +	snd_hdac_bus_enter_link_reset(bus);
> +	avs_hdac_clock_gating_enable(bus, true);
> +
> +	snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, false);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused avs_resume_common(struct avs_dev *adev, bool low_power, bool purge)
> +{
> +	struct hdac_bus *bus = &adev->base.core;
> +	struct hdac_ext_link *hlink;
> +	int ret;
> +
> +	snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, true);
> +	avs_hdac_bus_init_chip(bus, true);
> +
> +	snd_hdac_ext_bus_ppcap_enable(bus, true);
> +	snd_hdac_ext_bus_ppcap_int_enable(bus, true);
> +
> +	ret = avs_dsp_boot_firmware(adev, purge);
> +	if (ret < 0) {
> +		dev_err(adev->dev, "firmware boot failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* turn off the links that were off before suspend */
> +	list_for_each_entry(hlink, &bus->hlink_list, list) {
> +		if (!hlink->ref_count)
> +			snd_hdac_ext_bus_link_power_down(hlink);
> +	}
> +
> +	/* check dma status and clean up CORB/RIRB buffers */
> +	if (!bus->cmd_dma_state)
> +		snd_hdac_bus_stop_cmd_io(bus);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused avs_suspend(struct device *dev)
> +{
> +	return avs_suspend_common(to_avs_dev(dev), true);
> +}
> +
> +static int __maybe_unused avs_resume(struct device *dev)
> +{
> +	return avs_resume_common(to_avs_dev(dev), true, true);
> +}
> +
> +static int __maybe_unused avs_runtime_suspend(struct device *dev)
> +{
> +	return avs_suspend_common(to_avs_dev(dev), true);
> +}
> +
> +static int __maybe_unused avs_runtime_resume(struct device *dev)
> +{
> +	return avs_resume_common(to_avs_dev(dev), true, false);
> +}
> +
> +static int __maybe_unused avs_freeze(struct device *dev)
> +{
> +	return avs_suspend_common(to_avs_dev(dev), false);
> +}
> +static int __maybe_unused avs_thaw(struct device *dev)
> +{
> +	return avs_resume_common(to_avs_dev(dev), false, true);
> +}
> +
> +static int __maybe_unused avs_poweroff(struct device *dev)
> +{
> +	return avs_suspend_common(to_avs_dev(dev), false);
> +}
> +
> +static int __maybe_unused avs_restore(struct device *dev)
> +{
> +	return avs_resume_common(to_avs_dev(dev), false, true);
> +}
> +
> +static const struct dev_pm_ops avs_dev_pm = {
> +	.suspend = avs_suspend,
> +	.resume = avs_resume,

... all the 4 functions below seem unnecessary?

> +	.freeze = avs_freeze,
> +	.thaw = avs_thaw,
> +	.poweroff = avs_poweroff,
> +	.restore = avs_restore,

we've historically never used those, what drives this new usage?

on the SOF side, we've used prepare and complete, along with idle...


> +	SET_RUNTIME_PM_OPS(avs_runtime_suspend, avs_runtime_resume, NULL)
> +};
> +
>  static const struct pci_device_id avs_ids[] = {
>  	{ 0 }
>  };
> @@ -546,6 +668,9 @@ static struct pci_driver avs_pci_driver = {
>  	.id_table = avs_ids,
>  	.probe = avs_pci_probe,
>  	.remove = avs_pci_remove,
> +	.driver = {
> +		.pm = &avs_dev_pm,
> +	},
>  };
>  module_pci_driver(avs_pci_driver);
>