[Intel-gfx] [PATCH v8 6/8] drm/i915/guc: Update GuC suspend functionality in intel_uc_suspend

[Sagar Arun Kamble]

With this patch we disable GuC submission in i915_drm_suspend path.
This will destroy the client which will be setup back again. We also
reuse the complete sanitization done via intel_uc_runtime_suspend in
this path. Post i915_drm_resume, this state is recreated by
intel_uc_init_hw hence we need not have similar reuse for intel_uc_resume.
This also fixes issue where intel_uc_fini_hw was being called after GPU
reset happening in i915_gem_suspend during i915_driver_unload.

v2: Rebase w.r.t removal of GuC code restructuring. Added struct_mutex
protection for i915_guc_submission_disable.

v3: Rebase w.r.t updated GuC suspend function name.

v4: Added lockdep assert in i915_guc_submission_enable/disable.
Refined intel_uc_suspend to remove unnecessary locals and simplify
return. (Michal Winiarski)
Removed comment in guc_client_free about ignoring failure for
destroy_doorbell. (Oscar)
Rebase w.r.t i915_modparams change.

Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski at intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/i915_guc_submission.c | 15 ++++++++++++---
 drivers/gpu/drm/i915/intel_uc.c            | 11 +++++++----
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index d1d6c0d..0c56765 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -885,9 +885,6 @@ static void guc_client_free(struct i915_guc_client *client)
 	 * Be sure to drop any locks
 	 */
 
-	/* FIXME: in many cases, by the time we get here the GuC has been
-	 * reset, so we cannot destroy the doorbell properly. Ignore the
-	 * error message for now */
 	destroy_doorbell(client);
 	guc_stage_desc_fini(client->guc, client);
 	i915_gem_object_unpin_map(client->vma->obj);
@@ -1154,6 +1151,12 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
 		     sizeof(struct guc_wq_item) *
 		     I915_NUM_ENGINES > GUC_WQ_SIZE);
 
+	/*
+	 * Assert that drm.struct_mutex is held.
+	 * Needed for GuC client vma binding.
+	 */
+	lockdep_assert_held(&dev_priv->drm.struct_mutex);
+
 	if (!client) {
 		client = guc_client_alloc(dev_priv,
 					  INTEL_INFO(dev_priv)->ring_mask,
@@ -1204,6 +1207,12 @@ void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
 {
 	struct intel_guc *guc = &dev_priv->guc;
 
+	/*
+	 * Assert that drm.struct_mutex is held.
+	 * Needed for GuC client vma unbinding.
+	 */
+	lockdep_assert_held(&dev_priv->drm.struct_mutex);
+
 	guc_interrupts_release(dev_priv);
 
 	/* Revert back to manual ELSP submission */
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 7c34bc6..d710f0d 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -468,9 +468,6 @@ void intel_uc_fini_hw(struct drm_i915_private *dev_priv)
 	if (!i915_modparams.enable_guc_loading)
 		return;
 
-	if (i915_modparams.enable_guc_submission)
-		i915_guc_submission_disable(dev_priv);
-
 	guc_disable_communication(&dev_priv->guc);
 
 	if (i915_modparams.enable_guc_submission) {
@@ -549,7 +546,13 @@ int intel_uc_runtime_resume(struct drm_i915_private *dev_priv)
 
 int intel_uc_suspend(struct drm_i915_private *dev_priv)
 {
-	return intel_guc_suspend(dev_priv);
+	if (i915_modparams.enable_guc_submission) {
+		mutex_lock(&dev_priv->drm.struct_mutex);
+		i915_guc_submission_disable(dev_priv);
+		mutex_unlock(&dev_priv->drm.struct_mutex);
+	}
+
+	return intel_uc_runtime_suspend(dev_priv);
 }
 
 int intel_uc_resume(struct drm_i915_private *dev_priv)
-- 
1.9.1