[Intel-gfx] [PATCH] drm/i915/guc: Fix runtime suspend

[Chris Wilson]

We are not allowed to rpm_get() inside the runtime-suspend callback, so
split the intel_uc_suspend() into the core that assumes the caller holds
the wakeref (intel_uc_runtime_suspend), and one acquires the wakeref as
necessary (intel_uc_suspend).

Reported-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Fixes: 79ffac8599c4 ("drm/i915: Invert the GEM wakeref hierarchy")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c |  2 +-
 drivers/gpu/drm/i915/intel_uc.c | 25 +++++++++++++++++--------
 drivers/gpu/drm/i915/intel_uc.h |  1 +
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 21dac5a09fbe..74e46d129e6c 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2886,7 +2886,7 @@ static int intel_runtime_suspend(struct device *kdev)
 	 */
 	i915_gem_runtime_suspend(dev_priv);
 
-	intel_uc_suspend(dev_priv);
+	intel_uc_runtime_suspend(dev_priv);
 
 	intel_runtime_pm_disable_interrupts(dev_priv);
 
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 01ea36e3150c..1ee70df51627 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -481,22 +481,31 @@ void intel_uc_reset_prepare(struct drm_i915_private *i915)
 	intel_uc_sanitize(i915);
 }
 
-void intel_uc_suspend(struct drm_i915_private *i915)
+void intel_uc_runtime_suspend(struct drm_i915_private *i915)
 {
 	struct intel_guc *guc = &i915->guc;
-	intel_wakeref_t wakeref;
 	int err;
 
 	if (guc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
 		return;
 
-	with_intel_runtime_pm(i915, wakeref) {
-		err = intel_guc_suspend(guc);
-		if (err)
-			DRM_DEBUG_DRIVER("Failed to suspend GuC, err=%d", err);
+	err = intel_guc_suspend(guc);
+	if (err)
+		DRM_DEBUG_DRIVER("Failed to suspend GuC, err=%d", err);
 
-		guc_disable_communication(guc);
-	}
+	guc_disable_communication(guc);
+}
+
+void intel_uc_suspend(struct drm_i915_private *i915)
+{
+	struct intel_guc *guc = &i915->guc;
+	intel_wakeref_t wakeref;
+
+	if (guc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
+		return;
+
+	with_intel_runtime_pm(i915, wakeref)
+		intel_uc_runtime_suspend(i915);
 }
 
 int intel_uc_resume(struct drm_i915_private *i915)
diff --git a/drivers/gpu/drm/i915/intel_uc.h b/drivers/gpu/drm/i915/intel_uc.h
index c92436b1f1c5..3ea06c87dfcd 100644
--- a/drivers/gpu/drm/i915/intel_uc.h
+++ b/drivers/gpu/drm/i915/intel_uc.h
@@ -40,6 +40,7 @@ int intel_uc_init(struct drm_i915_private *dev_priv);
 void intel_uc_fini(struct drm_i915_private *dev_priv);
 void intel_uc_reset_prepare(struct drm_i915_private *i915);
 void intel_uc_suspend(struct drm_i915_private *i915);
+void intel_uc_runtime_suspend(struct drm_i915_private *i915);
 int intel_uc_resume(struct drm_i915_private *dev_priv);
 
 static inline bool intel_uc_is_using_guc(struct drm_i915_private *i915)
-- 
2.20.1