[PATCH 4.8 023/125] drm/i915/gen9: only add the planes actually affected by ddb changes

From: Greg Kroah-Hartman
Date: Sat Oct 29 2016 - 10:17:21 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>

commit be5c571b2ff3a164d2e14ccc100cb5b2b3d3fb7c upstream.

We were previously adding all the planes owned by the CRTC even when
the ddb partitioning didn't change for them. As a consequence, a lot
of functions were being called when we were just moving the cursor
around the screen, such as skylake_update_primary_plane().

This was causing flickering on the primary plane when moving the
cursor. I'm not 100% sure which operation caused the flickering, but
we were writing to a lot of registers, so it could be any of these
writes. With this patch, just moving the mouse won't add the primary
plane to the commit since it won't trigger a change in DDB
partitioning.

v2: Use skl_ddb_entry_equal() (Lyude).
v3: Change Reported-and-bisected-by: to Reported-by: for checkpatch

Fixes: 05a76d3d6ad1 ("drm/i915/skl: Ensure pipes with changed wms get added to the state")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97888
Cc: Mike Lothian <mike@xxxxxxxxxxxxxx>
Reported-by: Mike Lothian <mike@xxxxxxxxxxxxxx>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
Signed-off-by: Lyude <cpaul@xxxxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/1475177808-29955-1-git-send-email-paulo.r.zanoni@xxxxxxxxx
(cherry picked from commit 7f60e200e254cd53ad1bd74a56bdd23e813ac4b7)
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/i915/intel_pm.c | 37 ++++++++++++++++++++++++++++++++++++-
1 file changed, 36 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3940,6 +3940,41 @@ pipes_modified(struct drm_atomic_state *
return ret;
}

+int
+skl_ddb_add_affected_planes(struct intel_crtc_state *cstate)
+{
+ struct drm_atomic_state *state = cstate->base.state;
+ struct drm_device *dev = state->dev;
+ struct drm_crtc *crtc = cstate->base.crtc;
+ struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
+ struct skl_ddb_allocation *new_ddb = &intel_state->wm_results.ddb;
+ struct skl_ddb_allocation *cur_ddb = &dev_priv->wm.skl_hw.ddb;
+ struct drm_plane_state *plane_state;
+ struct drm_plane *plane;
+ enum pipe pipe = intel_crtc->pipe;
+ int id;
+
+ WARN_ON(!drm_atomic_get_existing_crtc_state(state, crtc));
+
+ drm_for_each_plane_mask(plane, dev, crtc->state->plane_mask) {
+ id = skl_wm_plane_id(to_intel_plane(plane));
+
+ if (skl_ddb_entry_equal(&cur_ddb->plane[pipe][id],
+ &new_ddb->plane[pipe][id]) &&
+ skl_ddb_entry_equal(&cur_ddb->y_plane[pipe][id],
+ &new_ddb->y_plane[pipe][id]))
+ continue;
+
+ plane_state = drm_atomic_get_plane_state(state, plane);
+ if (IS_ERR(plane_state))
+ return PTR_ERR(plane_state);
+ }
+
+ return 0;
+}
+
static int
skl_compute_ddb(struct drm_atomic_state *state)
{
@@ -4004,7 +4039,7 @@ skl_compute_ddb(struct drm_atomic_state
if (ret)
return ret;

- ret = drm_atomic_add_affected_planes(state, &intel_crtc->base);
+ ret = skl_ddb_add_affected_planes(cstate);
if (ret)
return ret;
}