[alsa-devel] [PATCH] ALSA: hda - do delayed suspend for HD-audio devices

[Takashi Iwai]

At Wed,  4 Dec 2013 20:04:25 -0500,
mengdong.lin at intel.com wrote:
> 
> From: Mengdong Lin <mengdong.lin at intel.com>
> 
> HD-Audio codecs tends to take a long time to supend and is time-consuming part
> in driver suspend. In this patch, codec suspending and the left operations are
> delayed to a worker thead, so that they can be done asynchronously in parallel
> with suspending of other devices. And azx_suspend_late() is defined as PM
> .suspend_late ops to wait for completion of the delayed suspending.
> 
> Credit goes to Liam Girdwood, who suggested this workaround.
> 
> Signed-off-by: Mengdong Lin <mengdong.lin at intel.com>

Did you try to set power.async_suspend flag?
The PM core has already async operation, so we don't have to implement
in the driver side.

(The codecs are a bit different issues because we handle them inside
 the hd-audio driver, so I merged your previous patches with workq.)


Takashi

> 
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index 80c5f14..aed4cdf 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -545,6 +545,11 @@ struct azx {
>  
>  	struct work_struct probe_work;
>  
> +#ifdef CONFIG_PM
> +	struct workqueue_struct *pm_wq; /* workqueue to delay controller PM */
> +	struct work_struct suspend_work; /* task to delay controller suspend */
> +#endif
> +
>  	/* reboot notifier (for mysterious hangup problem at power-down) */
>  	struct notifier_block reboot_notifier;
>  
> @@ -2908,20 +2913,11 @@ static int param_set_xint(const char *val, const struct kernel_param *kp)
>  /*
>   * power management
>   */
> -static int azx_suspend(struct device *dev)
> -{
> -	struct pci_dev *pci = to_pci_dev(dev);
> -	struct snd_card *card = dev_get_drvdata(dev);
> -	struct azx *chip = card->private_data;
> -	struct azx_pcm *p;
>  
> -	if (chip->disabled)
> -		return 0;
> +static int azx_suspend_continue(struct azx *chip)
> +{
> +	struct pci_dev *pci = chip->pci;
>  
> -	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
> -	azx_clear_irq_pending(chip);
> -	list_for_each_entry(p, &chip->pcm_list, list)
> -		snd_pcm_suspend_all(p->pcm);
>  	if (chip->initialized)
>  		snd_hda_suspend(chip->bus);
>  	azx_stop_chip(chip);
> @@ -2937,6 +2933,41 @@ static int azx_suspend(struct device *dev)
>  	pci_set_power_state(pci, PCI_D3hot);
>  	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
>  		hda_display_power(false);
> +
> +	return 0;
> +}
> +
> +static void azx_suspend_work(struct work_struct *work)
> +{
> +	azx_suspend_continue(container_of(work, struct azx, suspend_work));
> +}
> +
> +
> +static int azx_suspend(struct device *dev)
> +{
> +	struct snd_card *card = dev_get_drvdata(dev);
> +	struct azx *chip = card->private_data;
> +	struct azx_pcm *p;
> +
> +	if (chip->disabled)
> +		return 0;
> +
> +	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
> +	azx_clear_irq_pending(chip);
> +	list_for_each_entry(p, &chip->pcm_list, list)
> +		snd_pcm_suspend_all(p->pcm);
> +
> +	queue_work(chip->pm_wq, &chip->suspend_work);
> +	return 0;
> +}
> +
> +static int azx_suspend_late(struct device *dev)
> +{
> +	struct snd_card *card = dev_get_drvdata(dev);
> +	struct azx *chip = card->private_data;
> +
> +	flush_workqueue(chip->pm_wq);
> +
>  	return 0;
>  }
>  
> @@ -3057,6 +3088,7 @@ static int azx_runtime_idle(struct device *dev)
>  #ifdef CONFIG_PM
>  static const struct dev_pm_ops azx_pm = {
>  	SET_SYSTEM_SLEEP_PM_OPS(azx_suspend, azx_resume)
> +	.suspend_late = azx_suspend_late,
>  	SET_RUNTIME_PM_OPS(azx_runtime_suspend, azx_runtime_resume, azx_runtime_idle)
>  };
>  
> @@ -3272,6 +3304,12 @@ static int azx_free(struct azx *chip)
>  		hda_display_power(false);
>  		hda_i915_exit();
>  	}
> +
> +#ifdef CONFIG_PM
> +	if (chip->pm_wq)
> +		destroy_workqueue(chip->pm_wq);
> +#endif
> +
>  	kfree(chip);
>  
>  	return 0;
> @@ -3515,6 +3553,9 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci,
>  	};
>  	struct azx *chip;
>  	int err;
> +#ifdef CONFIG_PM
> +	char wqname[24];
> +#endif
>  
>  	*rchip = NULL;
>  
> @@ -3581,6 +3622,18 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci,
>  	/* continue probing in work context as may trigger request module */
>  	INIT_WORK(&chip->probe_work, azx_probe_work);
>  
> +#ifdef CONFIG_PM
> +	sprintf(wqname, "hda-azx-pm-wq%d", card->number);
> +	chip->pm_wq = create_workqueue("wqname");
> +	if (!chip->pm_wq) {
> +		snd_printk(KERN_ERR "cannot create PM workqueue\n");
> +		azx_free(chip);
> +		return -ENOMEM;
> +	}
> +
> +	INIT_WORK(&chip->suspend_work, azx_suspend_work);
> +#endif
> +
>  	*rchip = chip;
>  
>  	return 0;
> -- 
> 1.8.1.2
>