drm/i915/cdclk: Rework bw_min_cdclk handling

Update bw_min_cdclk directly from intel_bw_calc_min_cdclk()
rather than doing it later from intel_compute_min_cdclk().
This will allow better control over when to update the
cdclk. For now we preserve the current behaviour by allowing
the cdclk to decrease when any pipe needs to do a full modeset.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250923171943.7319-12-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index 5eae148e114b19d038de54e2d1a2847ace9a6851..e621dbef9c4902b98d15f3f2516ae79670f4e745 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -2873,8 +2873,13 @@ int intel_cdclk_update_bw_min_cdclk(struct intel_atomic_state *state,
 {
        struct intel_display *display = to_intel_display(state);
        struct intel_cdclk_state *cdclk_state;
+       bool allow_cdclk_decrease = intel_any_crtc_needs_modeset(state);
+       int ret;
 
-       if (new_min_cdclk <= old_min_cdclk)
+       if (new_min_cdclk == old_min_cdclk)
+               return 0;
+
+       if (!allow_cdclk_decrease && new_min_cdclk < old_min_cdclk)
                return 0;
 
        cdclk_state = intel_atomic_get_cdclk_state(state);
@@ -2883,9 +2888,18 @@ int intel_cdclk_update_bw_min_cdclk(struct intel_atomic_state *state,
 
        old_min_cdclk = cdclk_state->bw_min_cdclk;
 
-       if (new_min_cdclk <= old_min_cdclk)
+       if (new_min_cdclk == old_min_cdclk)
                return 0;
 
+       if (!allow_cdclk_decrease && new_min_cdclk < old_min_cdclk)
+               return 0;
+
+       cdclk_state->bw_min_cdclk = new_min_cdclk;
+
+       ret = intel_atomic_lock_global_state(&cdclk_state->base);
+       if (ret)
+               return ret;
+
        *need_cdclk_calc = true;
 
        drm_dbg_kms(display->drm,
@@ -2908,7 +2922,6 @@ static int intel_compute_min_cdclk(struct intel_atomic_state *state)
        struct intel_display *display = to_intel_display(state);
        struct intel_cdclk_state *cdclk_state =
                intel_atomic_get_new_cdclk_state(state);
-       const struct intel_bw_state *bw_state;
        struct intel_crtc *crtc;
        struct intel_crtc_state *crtc_state;
        int min_cdclk, i;
@@ -2931,23 +2944,8 @@ static int intel_compute_min_cdclk(struct intel_atomic_state *state)
                        return ret;
        }
 
-       bw_state = intel_atomic_get_new_bw_state(state);
-       if (bw_state) {
-               min_cdclk = intel_bw_min_cdclk(display, bw_state);
-
-               if (cdclk_state->bw_min_cdclk != min_cdclk) {
-                       int ret;
-
-                       cdclk_state->bw_min_cdclk = min_cdclk;
-
-                       ret = intel_atomic_lock_global_state(&cdclk_state->base);
-                       if (ret)
-                               return ret;
-               }
-       }
-
-       min_cdclk = max(cdclk_state->force_min_cdclk,
-                       cdclk_state->bw_min_cdclk);
+       min_cdclk = cdclk_state->force_min_cdclk;
+       min_cdclk = max(min_cdclk, cdclk_state->bw_min_cdclk);
        for_each_pipe(display, pipe)
                min_cdclk = max(min_cdclk, cdclk_state->min_cdclk[pipe]);