On Mon, Mar 25, 2024 at 01:23:26PM +0200, Stanislav Lisovskiy wrote: > According to BSpec we need to do correspondent MBUS updates before > or after DBUF reallocation, depending on whether we are enabling > or disabling mbus joining(typical scenario is swithing between > multiple and single displays). > > Also we need to be able to update dbuf min tracker and mdclk ratio > separately if mbus_join state didn't change, so lets add one > degree of freedom and make it possible. > > Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx> > --- > drivers/gpu/drm/i915/display/skl_watermark.c | 54 +++++++++++++------- > 1 file changed, 35 insertions(+), 19 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c > index bc341abcab2fe..2b947870527fc 100644 > --- a/drivers/gpu/drm/i915/display/skl_watermark.c > +++ b/drivers/gpu/drm/i915/display/skl_watermark.c > @@ -3570,16 +3570,38 @@ void intel_dbuf_mdclk_cdclk_ratio_update(struct drm_i915_private *i915, u8 ratio > DBUF_MIN_TRACKER_STATE_SERVICE(ratio - 1)); > } > > +static void intel_dbuf_mdclk_min_tracker_update(struct intel_atomic_state *state) > +{ > + struct drm_i915_private *i915 = to_i915(state->base.dev); > + const struct intel_dbuf_state *old_dbuf_state = > + intel_atomic_get_old_dbuf_state(state); > + const struct intel_dbuf_state *new_dbuf_state = > + intel_atomic_get_new_dbuf_state(state); > + > + if (DISPLAY_VER(i915) >= 20 && > + old_dbuf_state->mdclk_cdclk_ratio != new_dbuf_state->mdclk_cdclk_ratio) { > + /* > + * For Xe2LPD and beyond, when there is a change in the ratio > + * between MDCLK and CDCLK, updates to related registers need to > + * happen at a specific point in the CDCLK change sequence. In > + * that case, we defer to the call to > + * intel_dbuf_mdclk_cdclk_ratio_update() to the CDCLK logic. > + */ > + return; > + } That still needs to be removed or else we'll not update the ratio at all during the mbus_join changes. I don't think I saw any removal in subsequent patches. > + > + intel_dbuf_mdclk_cdclk_ratio_update(i915, new_dbuf_state->mdclk_cdclk_ratio, And it just occurred to me that this thing will in fact be wrong during the pre/post ddb hooks *and* cdclk is getting decreased from the post plane update hook. I can't immediately think of a super nice way to handle this. Perhaps the most stragithforward idea is to just get the mdclk/cdclk ratio from i915->display.cdclk.hw during the pre/post ddb hooks. cdclk serialization should guard against parallel updates from two both places and thus isplay.cdclk.hw should be safe to use. The other option would be to determine if a cdclk decrease is going to happen or not, and depending on that use the old vs. new dbuf_state when updating the ratio in the pre/post ddb hooks. > + new_dbuf_state->joined_mbus); > +} > + > /* > * Configure MBUS_CTL and all DBUF_CTL_S of each slice to join_mbus state before > * update the request state of all DBUS slices. > */ > -static void update_mbus_pre_enable(struct intel_atomic_state *state) > +static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state) > { > struct drm_i915_private *i915 = to_i915(state->base.dev); > u32 mbus_ctl; > - const struct intel_dbuf_state *old_dbuf_state = > - intel_atomic_get_old_dbuf_state(state); > const struct intel_dbuf_state *new_dbuf_state = > intel_atomic_get_new_dbuf_state(state); > > @@ -3600,21 +3622,6 @@ static void update_mbus_pre_enable(struct intel_atomic_state *state) > intel_de_rmw(i915, MBUS_CTL, > MBUS_HASHING_MODE_MASK | MBUS_JOIN | > MBUS_JOIN_PIPE_SELECT_MASK, mbus_ctl); > - > - if (DISPLAY_VER(i915) >= 20 && > - old_dbuf_state->mdclk_cdclk_ratio != new_dbuf_state->mdclk_cdclk_ratio) { > - /* > - * For Xe2LPD and beyond, when there is a change in the ratio > - * between MDCLK and CDCLK, updates to related registers need to > - * happen at a specific point in the CDCLK change sequence. In > - * that case, we defer to the call to > - * intel_dbuf_mdclk_cdclk_ratio_update() to the CDCLK logic. > - */ > - return; > - } > - > - intel_dbuf_mdclk_cdclk_ratio_update(i915, new_dbuf_state->mdclk_cdclk_ratio, > - new_dbuf_state->joined_mbus); > } > > void intel_dbuf_pre_plane_update(struct intel_atomic_state *state) > @@ -3632,7 +3639,11 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state) > > WARN_ON(!new_dbuf_state->base.changed); > > - update_mbus_pre_enable(state); > + if (!old_dbuf_state->joined_mbus && new_dbuf_state->joined_mbus) { I think you squashed that stuff into the wrong patch. This one should have a pure refactoring patch. > + intel_dbuf_mbus_join_update(state); > + intel_dbuf_mdclk_min_tracker_update(state); > + } > + > gen9_dbuf_slices_update(i915, > old_dbuf_state->enabled_slices | > new_dbuf_state->enabled_slices); > @@ -3653,6 +3664,11 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state) > > WARN_ON(!new_dbuf_state->base.changed); > > + if (old_dbuf_state->joined_mbus && !new_dbuf_state->joined_mbus) { > + intel_dbuf_mbus_join_update(state); > + intel_dbuf_mdclk_min_tracker_update(state); > + } > + > gen9_dbuf_slices_update(i915, > new_dbuf_state->enabled_slices); > } > -- > 2.37.3 -- Ville Syrjälä Intel