[Intel-gfx] [PATCH v2] drm/i915: clarify logging about reasons for disabling FBC

[Jani Nikula]

Previously FBC disabling due to per-chip default was logged as being
disabled per module parameter. Distinguish between the two.

v2: Don't even squawk in the debug log if FBC is explicitly disabled (Chris
Wilson).

Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c |    5 ++++-
 drivers/gpu/drm/i915/i915_drv.h     |    1 +
 drivers/gpu/drm/i915/intel_pm.c     |   15 ++++++++-------
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 0911fcd..275954c 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1294,7 +1294,10 @@ static int i915_fbc_status(struct seq_file *m, void *unused)
 			seq_printf(m, "multiple pipes are enabled");
 			break;
 		case FBC_MODULE_PARAM:
-			seq_printf(m, "disabled per module param (default off)");
+			seq_printf(m, "disabled per module param");
+			break;
+		case FBC_PER_CHIP_DEFAULT:
+			seq_printf(m, "per chip default is disabled");
 			break;
 		default:
 			seq_printf(m, "unknown reason");
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b1f6a09..1d552df 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -453,6 +453,7 @@ enum no_fbc_reason {
 	FBC_NOT_TILED, /* buffer not tiled */
 	FBC_MULTIPLE_PIPES, /* more than one pipe active */
 	FBC_MODULE_PARAM,
+	FBC_PER_CHIP_DEFAULT,
 };
 
 enum intel_pch {
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 61fee7f..9b2d7dd 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -437,13 +437,14 @@ void intel_update_fbc(struct drm_device *dev)
 
 	enable_fbc = i915_enable_fbc;
 	if (enable_fbc < 0) {
-		DRM_DEBUG_KMS("fbc set to per-chip default\n");
-		enable_fbc = 1;
-		if (INTEL_INFO(dev)->gen <= 6)
-			enable_fbc = 0;
-	}
-	if (!enable_fbc) {
-		DRM_DEBUG_KMS("fbc disabled per module param\n");
+		enable_fbc = INTEL_INFO(dev)->gen > 6;
+		DRM_DEBUG_KMS("fbc set to per-chip default: %s\n",
+			      enable_fbc ? "enabled" : "disabled");
+		if (!enable_fbc) {
+			dev_priv->no_fbc_reason = FBC_PER_CHIP_DEFAULT;
+			goto out_disable;
+		}
+	} else if (!enable_fbc) {
 		dev_priv->no_fbc_reason = FBC_MODULE_PARAM;
 		goto out_disable;
 	}
-- 
1.7.9.5