[PATCH v12 09/15] 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.

v5: Removed lockdep assert as mutex is needed by internal functions
which already have the asserts. (Chris)
Removed enable_guc_submission check for disabling GuC submission. (Chris)

v6: Rebase with enable_guc_submission related change done in earlier
newly introduced patches.

v7: Fixed intel_uc_resume to call intel_uc_runtime_resume and added
comment about need to enable submission later if needed. (Sagar)

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
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>
---
 drivers/gpu/drm/i915/i915_guc_submission.c |  3 ---
 drivers/gpu/drm/i915/intel_uc.c            | 18 ++++++++++++++----
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index ca6c4f9..ab1c382 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);
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index c54b302..feb149e 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -471,8 +471,6 @@ void intel_uc_fini_hw(struct drm_i915_private *dev_priv)
 {
 	guc_free_load_err_log(&dev_priv->guc);
 
-	i915_guc_submission_disable(dev_priv);
-
 	guc_disable_communication(&dev_priv->guc);
 
 	gen9_disable_guc_interrupts(dev_priv);
@@ -550,12 +548,24 @@ 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);
+	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)
 {
-	return intel_guc_resume(dev_priv);
+	/*
+	 * FIXME: intel_uc_suspend disables GuC submission. This is
+	 * needed for unload path as well. Also, GuC is reset at the end
+	 * of suspend which makes disabling submission post that not
+	 * possible. Hence we re-enable submission during intel_uc_init_hw.
+	 * Once reset at the end of suspend is removed we need to enable
+	 * GuC submission post resuming GuC.
+	 */
+	return intel_uc_runtime_resume(dev_priv);
 }
 
 void intel_uc_sanitize(struct drm_i915_private *dev_priv)
-- 
1.9.1