[Intel-gfx] [PATCH v2 09/15] drm/i915/guc: Move check for fast memcpy_wc to relay creation

[Michał Winiarski]

We only need those fast memcpy_wc when we're using relay to read
continuous GuC log. Let's prevent the user from creating a relay if we
know we won't be able to keep up with GuC.

v2: Adjust the return value (Michał)

Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_log.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_log.c b/drivers/gpu/drm/i915/intel_guc_log.c
index 62bf8da14b13..92a7bf0fd729 100644
--- a/drivers/gpu/drm/i915/intel_guc_log.c
+++ b/drivers/gpu/drm/i915/intel_guc_log.c
@@ -447,16 +447,6 @@ int intel_guc_log_create(struct intel_guc *guc)
 
 	GEM_BUG_ON(guc->log.vma);
 
-	/*
-	 * We require SSE 4.1 for fast reads from the GuC log buffer and
-	 * it should be present on the chipsets supporting GuC based
-	 * submisssions.
-	 */
-	if (WARN_ON(!i915_has_memcpy_from_wc())) {
-		ret = -EINVAL;
-		goto err;
-	}
-
 	vma = intel_guc_allocate_vma(guc, GUC_LOG_SIZE);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
@@ -570,6 +560,16 @@ int intel_guc_log_relay_open(struct intel_guc *guc)
 		goto out_unlock;
 	}
 
+	/*
+	 * We require SSE 4.1 for fast reads from the GuC log buffer and
+	 * it should be present on the chipsets supporting GuC based
+	 * submisssions.
+	 */
+	if (!i915_has_memcpy_from_wc()) {
+		ret = -ENXIO;
+		goto out_unlock;
+	}
+
 	ret = guc_log_relay_create(guc);
 	if (ret)
 		goto out_unlock;
-- 
2.14.3