[Intel-gfx] [PATCH] drm/i915: Avoid reading fbc registers in vain when fbc was never enabled.

[Rodrigo Vivi]

If it wasn't never enabled by kernel parameter or platform default
we can avoid reading registers so many times in vain

Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a988862..afcc284 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -339,6 +339,12 @@ bool intel_fbc_enabled(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	/* If it wasn't never enabled by kernel parameter or platform default
+	 * we can avoid reading registers so many times in vain
+	 */
+	if (!i915.enable_fbc)
+		return false;
+
 	if (!dev_priv->display.fbc_enabled)
 		return false;
 
-- 
1.9.3