drm/i915: Disable D3Cold in s2idle and runtime pm

s2idle and runtime pm puts the pci gfx device in D3Hot, ACPI runtime
monitors the pci tree,if it sees complete tree as D3Hot,it transitions
the device to D3Cold.But i915 do not have D3Cold support in S2idle or in
runtime pm. so disabling D3cold in above flows and its FIXME.

Added pci D3Cold enable/disable in s2idle and runtime suspend/resume
flows.
Signed-off-by: Tilak Tangudu <tilak.tangudu@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211115154054.3220476-1-tilak.tangudu@intel.com

drivers/gpu/drm/i915/i915_drv.c

@@ -1187,6 +1187,14 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
 		goto out;
 	}
 
+	/*
+	 * FIXME: Temporary hammer to avoid freezing the machine on our DGFX
+	 * This should be totally removed when we handle the pci states properly
+	 * on runtime PM and on s2idle cases.
+	 */
+	if (suspend_to_idle(dev_priv))
+		pci_d3cold_disable(pdev);
+
 	pci_disable_device(pdev);
 	/*
 	 * During hibernation on some platforms the BIOS may try to access
@@ -1350,6 +1358,8 @@ static int i915_drm_resume_early(struct drm_device *dev)
 
 	pci_set_master(pdev);
 
+	pci_d3cold_enable(pdev);
+
 	disable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
 
 	ret = vlv_resume_prepare(dev_priv, false);
@@ -1526,6 +1536,7 @@ static int intel_runtime_suspend(struct device *kdev)
 {
 	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
 	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
+	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
 	int ret;
 
 	if (drm_WARN_ON_ONCE(&dev_priv->drm, !HAS_RUNTIME_PM(dev_priv)))
@@ -1571,6 +1582,12 @@ static int intel_runtime_suspend(struct device *kdev)
 		drm_err(&dev_priv->drm,
 			"Unclaimed access detected prior to suspending\n");
 
+	/*
+	 * FIXME: Temporary hammer to avoid freezing the machine on our DGFX
+	 * This should be totally removed when we handle the pci states properly
+	 * on runtime PM and on s2idle cases.
+	 */
+	pci_d3cold_disable(pdev);
 	rpm->suspended = true;
 
 	/*
@@ -1609,6 +1626,7 @@ static int intel_runtime_resume(struct device *kdev)
 {
 	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
 	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
+	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
 	int ret;
 
 	if (drm_WARN_ON_ONCE(&dev_priv->drm, !HAS_RUNTIME_PM(dev_priv)))
@@ -1621,6 +1639,7 @@ static int intel_runtime_resume(struct device *kdev)
 
 	intel_opregion_notify_adapter(dev_priv, PCI_D0);
 	rpm->suspended = false;
+	pci_d3cold_enable(pdev);
 	if (intel_uncore_unclaimed_mmio(&dev_priv->uncore))
 		drm_dbg(&dev_priv->drm,
 			"Unclaimed access during suspend, bios?\n");