[PATCH 11/13] drm/i915: Implement vblank synchronized MBUS join changes

Gustavo Sousa gustavo.sousa at intel.com
Fri Mar 29 18:15:02 UTC 2024


Quoting Ville Syrjala (2024-03-27 14:45:42-03:00)
>From: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
>
>Currently we can't change MBUS join status without doing a modeset,
>because we are lacking mechanism to synchronize those with vblank.
>However then this means that we can't do a fastset, if there is a need
>to change MBUS join state. Fix that by implementing such change.
>We already call correspondent check and update at pre_plane dbuf update,
>so the only thing left is to have a non-modeset version of that.
>If active pipes stay the same then fastset is possible and only MBUS
>join state/ddb allocation updates would be committed.
>
>The full mbus/cdclk sequence will look as follows:
>1. disable pipes
>2. increase cdclk if necessary
> 2.1 reprogram cdclk
> 2.2 update dbuf tracker value
>3. enable mbus joining if necessary
> 3.1 update mbus_ctl
> 3.2 update dbuf tracker value
>4. reallocate dbuf for planes on active pipes
>5. disable mbus joining if necessary
> 5.1 update dbuf tracker value
> 5.2 update mbus_ctl
>6. enable pipes
>7. decrease cdclk if necessary
>  7.1 update dbuf tracker value
>  7.2 reprogram cdclk
>
>And in order to keep things in sync we need:
>Step 2:
>- mbus_join == old
>- mdclk/cdclk ratio == new
>Step 3:
>- mbus_join == new
>- mdclk/cdclk ratio == old when cdclk is changing in step 7
>- mdclk/cdclk ratio == new when cdclk is changing in step 2
>Step 5:
>- mbus_join == new
>- mdclk/cdclk ratio == old when cdclk is changing in step 7
>- mdclk/cdclk ratio == new when cdclk is changing in step 2
>Step 7:
>- mbus_join == new
>- mdclk/cdclk ratio == new
>
>v2: - Removed redundant parentheses(Ville Syrjälä)
>    - Constified new_crtc_state in intel_mbus_joined_pipe(Ville Syrjälä)
>    - Removed pipe_select variable(Ville Syrjälä)
>[v3: vsyrjala: Correctly sequence vs. cdclk updates,
>               properly describe the full sequence,
>               shuffle code around to make the diff more legible,
>               streamline a few things]
>
>Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
>Co-developed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>---
> drivers/gpu/drm/i915/display/intel_cdclk.c   |  11 ++
> drivers/gpu/drm/i915/display/intel_cdclk.h   |   1 +
> drivers/gpu/drm/i915/display/intel_display.c |   5 +-
> drivers/gpu/drm/i915/display/skl_watermark.c | 141 ++++++++++++-------
> drivers/gpu/drm/i915/display/skl_watermark.h |   3 +-
> 5 files changed, 112 insertions(+), 49 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
>index 4024118a7ffb..66c161d7b485 100644
>--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
>+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
>@@ -2576,6 +2576,17 @@ static void intel_cdclk_pcode_post_notify(struct intel_atomic_state *state)
>                            update_cdclk, update_pipe_count);
> }
> 
>+bool intel_cdclk_is_decreasing_later(struct intel_atomic_state *state)
>+{
>+        const struct intel_cdclk_state *old_cdclk_state =
>+                intel_atomic_get_old_cdclk_state(state);
>+        const struct intel_cdclk_state *new_cdclk_state =
>+                intel_atomic_get_new_cdclk_state(state);
>+
>+        return new_cdclk_state && !new_cdclk_state->disable_pipes &&
>+                new_cdclk_state->actual.cdclk < old_cdclk_state->actual.cdclk;
>+}
>+
> /**
>  * intel_set_cdclk_pre_plane_update - Push the CDCLK state to the hardware
>  * @state: intel atomic state
>diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.h b/drivers/gpu/drm/i915/display/intel_cdclk.h
>index 2843fc091086..5d4faf401774 100644
>--- a/drivers/gpu/drm/i915/display/intel_cdclk.h
>+++ b/drivers/gpu/drm/i915/display/intel_cdclk.h
>@@ -69,6 +69,7 @@ bool intel_cdclk_clock_changed(const struct intel_cdclk_config *a,
>                                const struct intel_cdclk_config *b);
> u8 intel_mdclk_cdclk_ratio(struct drm_i915_private *i915,
>                            const struct intel_cdclk_config *cdclk_config);
>+bool intel_cdclk_is_decreasing_later(struct intel_atomic_state *state);
> void intel_set_cdclk_pre_plane_update(struct intel_atomic_state *state);
> void intel_set_cdclk_post_plane_update(struct intel_atomic_state *state);
> void intel_cdclk_dump_config(struct drm_i915_private *i915,
>diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>index 4d6668a5f1ab..023cf4a77e6f 100644
>--- a/drivers/gpu/drm/i915/display/intel_display.c
>+++ b/drivers/gpu/drm/i915/display/intel_display.c
>@@ -6915,6 +6915,8 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
>                 intel_pre_update_crtc(state, crtc);
>         }
> 
>+        intel_dbuf_mbus_pre_ddb_update(state);
>+
>         while (update_pipes) {
>                 for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
>                                                     new_crtc_state, i) {
>@@ -6945,6 +6947,8 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
>                 }
>         }
> 
>+        intel_dbuf_mbus_post_ddb_update(state);
>+
>         update_pipes = modeset_pipes;
> 
>         /*
>@@ -7191,7 +7195,6 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
>         intel_encoders_update_prepare(state);
> 
>         intel_dbuf_pre_plane_update(state);
>-        intel_mbus_dbox_update(state);
> 
>         for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
>                 if (new_crtc_state->do_async_flip)
>diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
>index a118ecf9e532..ca0f1f89e6d9 100644
>--- a/drivers/gpu/drm/i915/display/skl_watermark.c
>+++ b/drivers/gpu/drm/i915/display/skl_watermark.c
>@@ -2636,13 +2636,6 @@ skl_compute_ddb(struct intel_atomic_state *state)
>                 if (ret)
>                         return ret;
> 
>-                if (old_dbuf_state->joined_mbus != new_dbuf_state->joined_mbus) {
>-                        /* TODO: Implement vblank synchronized MBUS joining changes */
>-                        ret = intel_modeset_all_pipes_late(state, "MBUS joining change");
>-                        if (ret)
>-                                return ret;
>-                }
>-
>                 drm_dbg_kms(&i915->drm,
>                             "Enabled dbuf slices 0x%x -> 0x%x (total dbuf slices 0x%x), mbus joined? %s->%s\n",
>                             old_dbuf_state->enabled_slices,
>@@ -3559,7 +3552,7 @@ static bool xelpdp_is_only_pipe_per_dbuf_bank(enum pipe pipe, u8 active_pipes)
>         return false;
> }
> 
>-void intel_mbus_dbox_update(struct intel_atomic_state *state)
>+static void intel_mbus_dbox_update(struct intel_atomic_state *state)
> {
>         struct drm_i915_private *i915 = to_i915(state->base.dev);
>         const struct intel_dbuf_state *new_dbuf_state, *old_dbuf_state;
>@@ -3640,6 +3633,9 @@ void intel_dbuf_mdclk_cdclk_ratio_update(struct drm_i915_private *i915, u8 ratio
> {
>         enum dbuf_slice slice;
> 
>+        if (!HAS_MBUS_JOINING(i915))
>+                return;
>+
>         if (DISPLAY_VER(i915) >= 20)
>                 intel_de_rmw(i915, MBUS_CTL, MBUS_TRANSLATION_THROTTLE_MIN_MASK,
>                              MBUS_TRANSLATION_THROTTLE_MIN(ratio - 1));
>@@ -3663,24 +3659,42 @@ static void intel_dbuf_mdclk_min_tracker_update(struct intel_atomic_state *state
>                 intel_atomic_get_old_dbuf_state(state);
>         const struct intel_dbuf_state *new_dbuf_state =
>                 intel_atomic_get_new_dbuf_state(state);
>+        int mdclk_cdclk_ratio;
> 
>-        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;
>+        if (intel_cdclk_is_decreasing_later(state)) {
>+                /* cdclk/mdclk will be changed later by intel_set_cdclk_post_plane_update() */
>+                mdclk_cdclk_ratio = old_dbuf_state->mdclk_cdclk_ratio;
>+        } else {
>+                /* cdclk/mdclk already changed by intel_set_cdclk_pre_plane_update() */
>+                mdclk_cdclk_ratio = new_dbuf_state->mdclk_cdclk_ratio;
>         }
> 
>-        intel_dbuf_mdclk_cdclk_ratio_update(i915, new_dbuf_state->mdclk_cdclk_ratio,
>+        intel_dbuf_mdclk_cdclk_ratio_update(i915, mdclk_cdclk_ratio,
>                                             new_dbuf_state->joined_mbus);

I get the feeling that this part actually belongs to the previous patch.

--
Gustavo Sousa

> }
> 
>-static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state)
>+static enum pipe intel_mbus_joined_pipe(struct intel_atomic_state *state,
>+                                        const struct intel_dbuf_state *dbuf_state)
>+{
>+        struct drm_i915_private *i915 = to_i915(state->base.dev);
>+        enum pipe pipe = ffs(dbuf_state->active_pipes) - 1;
>+        const struct intel_crtc_state *new_crtc_state;
>+        struct intel_crtc *crtc;
>+
>+        drm_WARN_ON(&i915->drm, !dbuf_state->joined_mbus);
>+        drm_WARN_ON(&i915->drm, !is_power_of_2(dbuf_state->active_pipes));
>+
>+        crtc = intel_crtc_for_pipe(i915, pipe);
>+        new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
>+
>+        if (new_crtc_state && !intel_crtc_needs_modeset(new_crtc_state))
>+                return pipe;
>+        else
>+                return INVALID_PIPE;
>+}
>+
>+static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state,
>+                                        enum pipe pipe)
> {
>         struct drm_i915_private *i915 = to_i915(state->base.dev);
>         const struct intel_dbuf_state *old_dbuf_state =
>@@ -3689,44 +3703,80 @@ static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state)
>                 intel_atomic_get_new_dbuf_state(state);
>         u32 mbus_ctl;
> 
>-        drm_dbg_kms(&i915->drm, "Changing mbus joined: %s -> %s\n",
>+        drm_dbg_kms(&i915->drm, "Changing mbus joined: %s -> %s (pipe: %c)\n",
>                     str_yes_no(old_dbuf_state->joined_mbus),
>-                    str_yes_no(new_dbuf_state->joined_mbus));
>+                    str_yes_no(new_dbuf_state->joined_mbus),
>+                    pipe != INVALID_PIPE ? pipe_name(pipe) : '*');
> 
>-        /*
>-         * TODO: Implement vblank synchronized MBUS joining changes.
>-         * Must be properly coordinated with dbuf reprogramming.
>-         */
>         if (new_dbuf_state->joined_mbus)
>-                mbus_ctl = MBUS_HASHING_MODE_1x4 | MBUS_JOIN |
>-                        MBUS_JOIN_PIPE_SELECT_NONE;
>+                mbus_ctl = MBUS_HASHING_MODE_1x4 | MBUS_JOIN;
>         else
>-                mbus_ctl = MBUS_HASHING_MODE_2x2 |
>-                        MBUS_JOIN_PIPE_SELECT_NONE;
>+                mbus_ctl = MBUS_HASHING_MODE_2x2;
>+
>+        if (pipe != INVALID_PIPE)
>+                mbus_ctl |= MBUS_JOIN_PIPE_SELECT(pipe);
>+        else
>+                mbus_ctl |= MBUS_JOIN_PIPE_SELECT_NONE;
> 
>         intel_de_rmw(i915, MBUS_CTL,
>                      MBUS_HASHING_MODE_MASK | MBUS_JOIN |
>                      MBUS_JOIN_PIPE_SELECT_MASK, mbus_ctl);
> }
> 
>-/*
>- * 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)
>+void intel_dbuf_mbus_pre_ddb_update(struct intel_atomic_state *state)
>+{
>+        const struct intel_dbuf_state *new_dbuf_state =
>+                intel_atomic_get_new_dbuf_state(state);
>+        const struct intel_dbuf_state *old_dbuf_state =
>+                intel_atomic_get_old_dbuf_state(state);
>+
>+        if (!new_dbuf_state)
>+                return;
>+
>+        if (!old_dbuf_state->joined_mbus && new_dbuf_state->joined_mbus) {
>+                enum pipe pipe = intel_mbus_joined_pipe(state, new_dbuf_state);
>+
>+                WARN_ON(!new_dbuf_state->base.changed);
>+
>+                intel_dbuf_mbus_join_update(state, pipe);
>+                intel_mbus_dbox_update(state);
>+                intel_dbuf_mdclk_min_tracker_update(state);
>+        }
>+}
>+
>+void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state)
> {
>         struct drm_i915_private *i915 = to_i915(state->base.dev);
>+        const struct intel_dbuf_state *new_dbuf_state =
>+                intel_atomic_get_new_dbuf_state(state);
>+        const struct intel_dbuf_state *old_dbuf_state =
>+                intel_atomic_get_old_dbuf_state(state);
> 
>-        if (!HAS_MBUS_JOINING(i915))
>+        if (!new_dbuf_state)
>                 return;
> 
>-        /*
>-         * TODO: Implement vblank synchronized MBUS joining changes.
>-         * Must be properly coordinated with dbuf reprogramming.
>-         */
>-        intel_dbuf_mbus_join_update(state);
>+        if (old_dbuf_state->joined_mbus && !new_dbuf_state->joined_mbus) {
>+                enum pipe pipe = intel_mbus_joined_pipe(state, old_dbuf_state);
>+
>+                WARN_ON(!new_dbuf_state->base.changed);
>+
>+                intel_dbuf_mdclk_min_tracker_update(state);
>+                intel_mbus_dbox_update(state);
>+                intel_dbuf_mbus_join_update(state, pipe);
>+
>+                if (pipe != INVALID_PIPE) {
>+                        struct intel_crtc *crtc = intel_crtc_for_pipe(i915, pipe);
>+
>+                        intel_crtc_wait_for_next_vblank(crtc);
>+                }
>+        } else if (old_dbuf_state->joined_mbus == new_dbuf_state->joined_mbus &&
>+                   old_dbuf_state->active_pipes != new_dbuf_state->active_pipes) {
>+                WARN_ON(!new_dbuf_state->base.changed);
>+
>+                intel_dbuf_mdclk_min_tracker_update(state);
>+                intel_mbus_dbox_update(state);
>+        }
> 
>-        intel_dbuf_mdclk_min_tracker_update(state);
> }
> 
> void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
>@@ -3738,13 +3788,11 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
>                 intel_atomic_get_old_dbuf_state(state);
> 
>         if (!new_dbuf_state ||
>-            (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices &&
>-             new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus))
>+            new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices)
>                 return;
> 
>         WARN_ON(!new_dbuf_state->base.changed);
> 
>-        update_mbus_pre_enable(state);
>         gen9_dbuf_slices_update(i915,
>                                 old_dbuf_state->enabled_slices |
>                                 new_dbuf_state->enabled_slices);
>@@ -3759,8 +3807,7 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
>                 intel_atomic_get_old_dbuf_state(state);
> 
>         if (!new_dbuf_state ||
>-            (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices &&
>-             new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus))
>+            new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices)
>                 return;
> 
>         WARN_ON(!new_dbuf_state->base.changed);
>diff --git a/drivers/gpu/drm/i915/display/skl_watermark.h b/drivers/gpu/drm/i915/display/skl_watermark.h
>index bf7516620ab6..3323a1d973f9 100644
>--- a/drivers/gpu/drm/i915/display/skl_watermark.h
>+++ b/drivers/gpu/drm/i915/display/skl_watermark.h
>@@ -79,7 +79,8 @@ int intel_dbuf_state_set_mdclk_cdclk_ratio(struct intel_atomic_state *state, u8
> void intel_dbuf_pre_plane_update(struct intel_atomic_state *state);
> void intel_dbuf_post_plane_update(struct intel_atomic_state *state);
> void intel_dbuf_mdclk_cdclk_ratio_update(struct drm_i915_private *i915, u8 ratio, bool joined_mbus);
>-void intel_mbus_dbox_update(struct intel_atomic_state *state);
>+void intel_dbuf_mbus_pre_ddb_update(struct intel_atomic_state *state);
>+void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state);
> 
> #endif /* __SKL_WATERMARK_H__ */
> 
>-- 
>2.43.2
>


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