[Intel-gfx] [PATCH 8/8] drm/i915 : Add D3COLD OFF support

[Imre Deak]

On Thu, Jul 21, 2022 at 03:29:55PM +0530, tilak.tangudu at intel.com wrote:
> [...]
> @@ -1706,6 +1716,12 @@ static int intel_runtime_suspend(struct device *kdev)
>  	if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv))
>  		intel_hpd_poll_enable(dev_priv);
>  
> +	if (rpm->d3_state == INTEL_D3COLD_OFF) {
> +		i915_save_pci_state(pdev);
> +		pci_disable_device(pdev);
> +		pci_set_power_state(pdev, PCI_D3cold);
> +	}

Could you add a code comment describing why the above is required? For
standard PCI devices pci_pm_runtime_suspend() should do this except for
calling pci_disable_device().

> +
>  	drm_dbg(&dev_priv->drm, "Device suspended\n");
>  	return 0;
>  }
> @@ -1713,6 +1729,7 @@ static int intel_runtime_suspend(struct device *kdev)
>  static int intel_runtime_resume(struct device *kdev)
>  {
>  	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
> +	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
>  	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
>  	int ret;
>  
> @@ -1724,7 +1741,25 @@ static int intel_runtime_resume(struct device *kdev)
>  	drm_WARN_ON_ONCE(&dev_priv->drm, atomic_read(&rpm->wakeref_count));
>  	disable_rpm_wakeref_asserts(rpm);
>  
> -	intel_opregion_notify_adapter(dev_priv, PCI_D0);
> +	if (rpm->d3_state == INTEL_D3COLD_OFF) {
> +		ret = pci_set_power_state(pdev, PCI_D0);
> +		if (ret) {
> +			drm_err(&dev_priv->drm,
> +				"failed to set PCI D0 power state (%d)\n", ret);
> +			goto out;
> +		}
> +
> +		i915_load_pci_state(pdev);
> +
> +		ret = pci_enable_device(pdev);
> +		if (ret)
> +			goto out;
> +		pci_set_master(pdev);
> +		intel_opregion_resume(dev_priv);
> +	} else {
> +		intel_opregion_notify_adapter(dev_priv, PCI_D0);
> +	}
> +
>  	rpm->suspended = false;
>  	if (intel_uncore_unclaimed_mmio(&dev_priv->uncore))
>  		drm_dbg(&dev_priv->drm,
> @@ -1742,8 +1777,20 @@ static int intel_runtime_resume(struct device *kdev)
>  	 * No point of rolling back things in case of an error, as the best
>  	 * we can do is to hope that things will still work (and disable RPM).
>  	 */
> -	intel_gt_runtime_resume(to_gt(dev_priv));
> +	if (rpm->d3_state == INTEL_D3COLD_OFF) {
> +		ret = i915_pcode_init(dev_priv);
> +		if (ret)
> +			goto out;
>  
> +		sanitize_gpu(dev_priv);
> +		ret = i915_ggtt_enable_hw(dev_priv);
> +		if (ret)
> +			drm_err(&dev_priv->drm, "failed to re-enable GGTT\n");
> +		i915_ggtt_resume(to_gt(dev_priv)->ggtt);
> +		i915_gem_resume(dev_priv);
> +	} else {
> +		intel_gt_runtime_resume(to_gt(dev_priv));
> +	}
>  	/*
>  	 * On VLV/CHV display interrupts are part of the display
>  	 * power well, so hpd is reinitialized from there. For
> @@ -1756,6 +1803,7 @@ static int intel_runtime_resume(struct device *kdev)
>  
>  	intel_enable_ipc(dev_priv);
>  
> +out:
>  	enable_rpm_wakeref_asserts(rpm);
>  
>  	if (ret)
> -- 
> 2.25.1
>