[Intel-gfx] [RFC 2/3] drm/i915/guc: Omit guc_init_doorbell_hw during driver load

[Michel Thierry]

During driver load we create the GuC clients and allocate their
doorbells just before executing guc_init_doorbell_hw; but since we just
created these doorbells, how can they be out of sync?
This code has had more than enough refactoring (2 more still in progress)
so I would not be surprised if calling guc_init_doorbell_hw made sense at
some point, but not anymore.

The resume path is different, in this case the driver doesn't
recreate clients, and it is still reasonable to validate/reallocate the
doorbells in order to confirm that they still belong to the clients.

And probably guc_init_doorbell_hw is no longer the right name, but I'll
leave that to someone else.

Signed-off-by: Michel Thierry <michel.thierry at intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble at intel.com>
Cc: Sujaritha Sundaresan <sujaritha.sundaresan at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Oscar Mateo <oscar.mateo at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_guc_submission.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 5d6576e01a91..d6762ca42cf1 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -1424,16 +1424,16 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
 	} else {
 		guc_reset_wq(guc->execbuf_client);
 		guc_reset_wq(guc->preempt_client);
+
+		err = guc_init_doorbell_hw(guc);
+		if (err)
+			goto err_free_clients;
 	}
 
 	err = intel_guc_sample_forcewake(guc);
 	if (err)
 		goto err_free_clients;
 
-	err = guc_init_doorbell_hw(guc);
-	if (err)
-		goto err_free_clients;
-
 	/* Take over from manual control of ELSP (execlists) */
 	guc_interrupts_capture(dev_priv);
 
-- 
2.15.0