drm/i915: Make switching to the same CRC source a no-op

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 58c6fd4c8610..8c750d5110a1 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1804,6 +1804,7 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
                                enum intel_pipe_crc_source source)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
+        struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
         u32 val;
 
 
@@ -1812,7 +1813,10 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
         if (!IS_IVYBRIDGE(dev))
                 return -ENODEV;
 
-        dev_priv->pipe_crc[pipe].source = source;
+        if (pipe_crc->source == source)
+                return 0;
+
+        pipe_crc->source = source;
 
         switch (source) {
         case INTEL_PIPE_CRC_SOURCE_PLANE1: