[Intel-gfx] [PATCH 3/4] drm/i915/guc: do not print drbreg on error

[Daniele Ceraolo Spurio]

The only content of the register apart from the valid bit is the lower
part of the physical memory address. If the valid bit is 0 the address
is meaningless, while if it is 1 we don't know which descriptor it came
from (since the doorbell is in an unexpected state) so we can't match it
to an expected value. Since we already print the state of the valid bit,
stop priniting the full register contents as they're just confusing.
While at it, move the checking of the valid bit to a common helper.

Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_submission.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index 8c3b5a9facee..cba84480dad9 100644
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -192,6 +192,12 @@ static struct guc_doorbell_info *__get_doorbell(struct intel_guc_client *client)
 	return client->vaddr + client->doorbell_offset;
 }
 
+static bool __doorbell_valid(struct intel_guc *guc, u16 db_id)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	return I915_READ(GEN8_DRBREGL(db_id)) & GEN8_DRB_VALID;
+}
+
 static void __init_doorbell(struct intel_guc_client *client)
 {
 	struct guc_doorbell_info *doorbell;
@@ -203,7 +209,6 @@ static void __init_doorbell(struct intel_guc_client *client)
 
 static void __fini_doorbell(struct intel_guc_client *client)
 {
-	struct drm_i915_private *dev_priv = guc_to_i915(client->guc);
 	struct guc_doorbell_info *doorbell;
 	u16 db_id = client->doorbell_id;
 
@@ -214,7 +219,7 @@ static void __fini_doorbell(struct intel_guc_client *client)
 	 * to go to zero after updating db_status before we call the GuC to
 	 * release the doorbell
 	 */
-	if (wait_for_us(!(I915_READ(GEN8_DRBREGL(db_id)) & GEN8_DRB_VALID), 10))
+	if (wait_for_us(!__doorbell_valid(client->guc, db_id), 10))
 		WARN_ONCE(true, "Doorbell never became invalid after disable\n");
 }
 
@@ -866,20 +871,17 @@ guc_reset_prepare(struct intel_engine_cs *engine)
 /* Check that a doorbell register is in the expected state */
 static bool doorbell_ok(struct intel_guc *guc, u16 db_id)
 {
-	struct drm_i915_private *dev_priv = guc_to_i915(guc);
-	u32 drbregl;
 	bool valid;
 
 	GEM_BUG_ON(db_id >= GUC_DOORBELL_INVALID);
 
-	drbregl = I915_READ(GEN8_DRBREGL(db_id));
-	valid = drbregl & GEN8_DRB_VALID;
+	valid = __doorbell_valid(guc, db_id);
 
 	if (test_bit(db_id, guc->doorbell_bitmap) == valid)
 		return true;
 
-	DRM_DEBUG_DRIVER("Doorbell %d has unexpected state (0x%x): valid=%s\n",
-			 db_id, drbregl, yesno(valid));
+	DRM_DEBUG_DRIVER("Doorbell %d has unexpected state: valid=%s\n",
+			 db_id, yesno(valid));
 
 	return false;
 }
-- 
2.19.0