drm/i915/cdclk: Rework crtc min_cdclk handling

Update crtc min_cdclk directly from when calling
intel_cdclk_update_crtc_min_cdclk() rather than doing it later
from intel_compute_min_cdclk().

This will eg. 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/20250923171943.7319-15-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 7f62fa25ce0ce1d4704d751b91ddd06092645387..1241dd0fb343e8161be0ddcf140312acd72385b0 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -2844,8 +2844,13 @@ static int intel_cdclk_update_crtc_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)
+               return 0;
 
-       if (new_min_cdclk <= old_min_cdclk)
+       if (!allow_cdclk_decrease && new_min_cdclk < old_min_cdclk)
                return 0;
 
        cdclk_state = intel_atomic_get_cdclk_state(state);
@@ -2854,9 +2859,18 @@ static int intel_cdclk_update_crtc_min_cdclk(struct intel_atomic_state *state,
 
        old_min_cdclk = cdclk_state->min_cdclk[crtc->pipe];
 
-       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->min_cdclk[crtc->pipe] = 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,
@@ -2922,27 +2936,8 @@ 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);
-       struct intel_crtc *crtc;
-       struct intel_crtc_state *crtc_state;
-       int min_cdclk, i;
        enum pipe pipe;
-
-       for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
-               int ret;
-
-               min_cdclk = intel_crtc_compute_min_cdclk(crtc_state);
-               if (min_cdclk < 0)
-                       return min_cdclk;
-
-               if (cdclk_state->min_cdclk[crtc->pipe] == min_cdclk)
-                       continue;
-
-               cdclk_state->min_cdclk[crtc->pipe] = min_cdclk;
-
-               ret = intel_atomic_lock_global_state(&cdclk_state->base);
-               if (ret)
-                       return ret;
-       }
+       int min_cdclk;
 
        min_cdclk = cdclk_state->force_min_cdclk;
        min_cdclk = max(min_cdclk, cdclk_state->bw_min_cdclk);