drm/i915: Skip watermark merging for inactive pipes

Even though the inactive pipes should have their watermarks set to all 0
with enable=true, we can possibly shave off a few cycles by completely
skipping the merge procedure for inactive pipes.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 855c01b2b0c1..c0c0390dd52a 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2206,8 +2206,11 @@ static void ilk_merge_wm_level(struct drm_device *dev,
         const struct intel_crtc *intel_crtc;
 
         list_for_each_entry(intel_crtc, &dev->mode_config.crtc_list, base.head) {
-                const struct intel_wm_level *wm =
-                        &intel_crtc->wm.active.wm[level];
+                const struct intel_pipe_wm *active = &intel_crtc->wm.active;
+                const struct intel_wm_level *wm = &active->wm[level];
+
+                if (!active->pipe_enabled)
+                        continue;
 
                 if (!wm->enable)
                         return;