[Intel-gfx] [PATCH] drm/i915: fix suspend/resume for GENs w/o runtime PM support

[Imre Deak]

Before sharing common parts between the system and runtime s/r
handlers we WARNed if the runtime s/r handlers were called on GENs that
didn't support RPM. But this WARN is not correct if the same handler is
called from the system s/r path, since that can happen on any platform.
This also broke system s/r on old platforms.

The issue was introduced in

commit 016970beb05da6285c2f3ed2bee1c676cb75972e
Author: Sagar Kamble <sagar.a.kamble at intel.com>
Date:   Wed Aug 13 23:07:06 2014 +0530

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82751
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 117f5c1..f646f34 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -499,7 +499,8 @@ bool i915_semaphore_is_enabled(struct drm_device *dev)
 }
 
 
-static int intel_suspend_complete(struct drm_i915_private *dev_priv);
+static int intel_suspend_complete(struct drm_i915_private *dev_priv,
+				  bool rpm_suspend);
 static int intel_resume_prepare(struct drm_i915_private *dev_priv,
 				bool rpm_resume);
 
@@ -909,7 +910,7 @@ static int i915_pm_suspend_late(struct device *dev)
 	if (drm_dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 		return 0;
 
-	ret = intel_suspend_complete(dev_priv);
+	ret = intel_suspend_complete(dev_priv, false);
 
 	if (ret)
 		DRM_ERROR("Suspend complete failed: %d\n", ret);
@@ -1410,7 +1411,7 @@ static int intel_runtime_suspend(struct device *device)
 	cancel_work_sync(&dev_priv->rps.work);
 	intel_runtime_pm_disable_interrupts(dev);
 
-	ret = intel_suspend_complete(dev_priv);
+	ret = intel_suspend_complete(dev_priv, true);
 	if (ret) {
 		DRM_ERROR("Runtime suspend failed, disabling it (%d)\n", ret);
 		intel_runtime_pm_restore_interrupts(dev);
@@ -1471,10 +1472,11 @@ static int intel_runtime_resume(struct device *device)
  * This function implements common functionality of runtime and system
  * suspend sequence.
  */
-static int intel_suspend_complete(struct drm_i915_private *dev_priv)
+static int intel_suspend_complete(struct drm_i915_private *dev_priv,
+				  bool rpm_suspend)
 {
 	struct drm_device *dev = dev_priv->dev;
-	int ret;
+	int ret = 0;
 
 	if (IS_GEN6(dev)) {
 		ret = 0;
@@ -1482,7 +1484,7 @@ static int intel_suspend_complete(struct drm_i915_private *dev_priv)
 		ret = hsw_suspend_complete(dev_priv);
 	} else if (IS_VALLEYVIEW(dev)) {
 		ret = vlv_suspend_complete(dev_priv);
-	} else {
+	} else if (rpm_suspend) {
 		ret = -ENODEV;
 		WARN_ON(1);
 	}
@@ -1499,7 +1501,7 @@ static int intel_resume_prepare(struct drm_i915_private *dev_priv,
 				bool rpm_resume)
 {
 	struct drm_device *dev = dev_priv->dev;
-	int ret;
+	int ret = 0;
 
 	if (IS_GEN6(dev)) {
 		ret = snb_resume_prepare(dev_priv, rpm_resume);
@@ -1507,7 +1509,7 @@ static int intel_resume_prepare(struct drm_i915_private *dev_priv,
 		ret = hsw_resume_prepare(dev_priv, rpm_resume);
 	} else if (IS_VALLEYVIEW(dev)) {
 		ret = vlv_resume_prepare(dev_priv, rpm_resume);
-	} else {
+	} else if (rpm_resume) {
 		WARN_ON(1);
 		ret = -ENODEV;
 	}
-- 
1.8.4