Manual pipe flushes are only necessary in order to make sure that we prevent pipes with changed ddb allocations from overlapping from one another at any point in time. Additionally, forcing us to wait for the next vblank every time we have to update the watermark values because the cursor was moving between screens will introduce a rather noticable lag for users.
Signed-off-by: Lyude cpaul@redhat.com Cc: stable@vger.kernel.org Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Radhakrishna Sripada radhakrishna.sripada@intel.com Cc: Hans de Goede hdegoede@redhat.com cpaul@redhat.com Cc: Matt Roper matthew.d.roper@intel.com --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_pm.c | 31 +++++++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index c97724d..9e1e045 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1597,6 +1597,7 @@ struct skl_ddb_allocation {
struct skl_wm_values { unsigned dirty_pipes; + bool ddb_changed; struct skl_ddb_allocation ddb; uint32_t wm_linetime[I915_MAX_PIPES]; uint32_t plane[I915_MAX_PIPES][I915_MAX_PLANES][8]; diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 2e31df4..4178bdd 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3809,6 +3809,12 @@ static void skl_flush_wm_values(struct drm_i915_private *dev_priv, new_ddb = &new_values->ddb; cur_ddb = &dev_priv->wm.skl_hw.ddb;
+ /* We only ever need to flush when the ddb allocations change */ + if (!new_values->ddb_changed) + return; + + new_values->ddb_changed = false; + /* * First pass: flush the pipes with the new allocation contained into * the old space. @@ -3926,6 +3932,22 @@ pipes_modified(struct drm_atomic_state *state) return ret; }
+static bool +skl_pipe_ddb_changed(struct skl_ddb_allocation *old, + struct skl_ddb_allocation *new, + enum pipe pipe) +{ + if (memcmp(&old->pipe[pipe], &new->pipe[pipe], + sizeof(old->pipe[pipe])) != 0 || + memcmp(&old->plane[pipe], &new->plane[pipe], + sizeof(old->plane[pipe])) != 0 || + memcmp(&old->y_plane[pipe], &new->y_plane[pipe], + sizeof(old->y_plane[pipe])) != 0) + return true; + + return false; +} + static int skl_compute_ddb(struct drm_atomic_state *state) { @@ -3933,7 +3955,8 @@ skl_compute_ddb(struct drm_atomic_state *state) struct drm_i915_private *dev_priv = to_i915(dev); struct intel_atomic_state *intel_state = to_intel_atomic_state(state); struct intel_crtc *intel_crtc; - struct skl_ddb_allocation *ddb = &intel_state->wm_results.ddb; + struct skl_ddb_allocation *new_ddb = &intel_state->wm_results.ddb; + struct skl_ddb_allocation *old_ddb = &dev_priv->wm.skl_hw.ddb; uint32_t realloc_pipes = pipes_modified(state); int ret;
@@ -3971,9 +3994,13 @@ skl_compute_ddb(struct drm_atomic_state *state) if (IS_ERR(cstate)) return PTR_ERR(cstate);
- ret = skl_allocate_pipe_ddb(cstate, ddb); + ret = skl_allocate_pipe_ddb(cstate, new_ddb); if (ret) return ret; + + if (!intel_state->wm_results.ddb_changed && + skl_pipe_ddb_changed(old_ddb, new_ddb, intel_crtc->pipe)) + intel_state->wm_results.ddb_changed = true; }
return 0;