[PATCH 2/6] drm/i915/pm: Hoist pci_save_state()+pci_set_power_state() to the end of pm _late() hook

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

driver/pci does the pci_save_state()+pci_set_power_state() from the
_noirq() pm hooks. Move our manual calls (needed for the hibernate+D3
workaround with buggy BIOSes) towards that same point. We currently
have no _noirq() hooks, so end of _late() hooks is the best we can
do right now.

Cc: Bjorn Helgaas <bhelgaas at google.com>
Cc: "Rafael J. Wysocki" <rafael at kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: linux-pci at vger.kernel.org
Cc: intel-gfx at lists.freedesktop.org
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_driver.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index 6dc0104a3e36..9d557ff8adf5 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -1015,7 +1015,6 @@ static int i915_drm_suspend(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_display *display = &dev_priv->display;
-	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
 	pci_power_t opregion_target_state;
 
 	disable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
@@ -1029,8 +1028,6 @@ static int i915_drm_suspend(struct drm_device *dev)
 		intel_display_driver_disable_user_access(dev_priv);
 	}
 
-	pci_save_state(pdev);
-
 	intel_display_driver_suspend(dev_priv);
 
 	intel_dp_mst_suspend(dev_priv);
@@ -1090,10 +1087,16 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
 		drm_err(&dev_priv->drm, "Suspend complete failed: %d\n", ret);
 		intel_power_domains_resume(dev_priv);
 
-		goto out;
+		goto fail;
 	}
 
+	enable_rpm_wakeref_asserts(rpm);
+
+	if (!dev_priv->uncore.user_forcewake_count)
+		intel_runtime_pm_driver_release(rpm);
+
 	pci_disable_device(pdev);
+
 	/*
 	 * During hibernation on some platforms the BIOS may try to access
 	 * the device even though it's already in D3 and hang the machine. So
@@ -1105,11 +1108,17 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
 	 * Lenovo Thinkpad X301, X61s, X60, T60, X41
 	 * Fujitsu FSC S7110
 	 * Acer Aspire 1830T
+	 *
+	 * pci_save_state() is needed to prevent driver/pci from
+	 * automagically putting the device into D3.
 	 */
+	pci_save_state(pdev);
 	if (!(hibernation && GRAPHICS_VER(dev_priv) < 6))
 		pci_set_power_state(pdev, PCI_D3hot);
 
-out:
+	return 0;
+
+fail:
 	enable_rpm_wakeref_asserts(rpm);
 	if (!dev_priv->uncore.user_forcewake_count)
 		intel_runtime_pm_driver_release(rpm);
-- 
2.44.2