Re: [RESEND, 09/22] drm/i915/vrr: Increment DC balance flip count on every flip

[Nautiyal, Ankit K]

On 11/3/2025 10:59 AM, Mitul Golani wrote:

Increment DC Balance Flip count before every send push to indicate
DMC firmware about new flip occurrence. This is tracked separately
from legacy FLIP_COUNT register.

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.gol...@intel.com>
---
  drivers/gpu/drm/i915/display/intel_color.c   |  1 +
  drivers/gpu/drm/i915/display/intel_display.c |  1 +
  drivers/gpu/drm/i915/display/intel_vrr.c     | 15 +++++++++++++++
  drivers/gpu/drm/i915/display/intel_vrr.h     |  3 +++
  4 files changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_color.c 
b/drivers/gpu/drm/i915/display/intel_color.c
index 1e97020e7304..47a732ae2448 100644
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -2012,6 +2012,7 @@ void intel_color_prepare_commit(struct intel_atomic_state 
*state,
        display->funcs.color->load_luts(crtc_state);

if (crtc_state->use_dsb && intel_color_uses_chained_dsb(crtc_state)) {

+               intel_vrr_dcb_increment_flip_count(crtc_state, crtc);
                intel_vrr_send_push(crtc_state->dsb_color, crtc_state);
                intel_dsb_wait_for_delayed_vblank(state, crtc_state->dsb_color);
                intel_vrr_check_push_sent(crtc_state->dsb_color, crtc_state);
diff --git a/drivers/gpu/drm/i915/display/intel_display.c 
b/drivers/gpu/drm/i915/display/intel_display.c
index a00625f882e8..1a3e7a6e4ab7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7366,6 +7366,7 @@ static void intel_atomic_dsb_finish(struct 
intel_atomic_state *state,
        if (new_crtc_state->use_dsb && 
!intel_color_uses_chained_dsb(new_crtc_state)) {
                intel_dsb_wait_vblanks(new_crtc_state->dsb_commit, 1);

+ intel_vrr_dcb_increment_flip_count(new_crtc_state, crtc);

                intel_vrr_send_push(new_crtc_state->dsb_commit, new_crtc_state);
                intel_dsb_wait_for_delayed_vblank(state, 
new_crtc_state->dsb_commit);
                intel_vrr_check_push_sent(new_crtc_state->dsb_commit,
diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c 
b/drivers/gpu/drm/i915/display/intel_vrr.c
index 2948abc90c69..87bd722aa32d 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -14,6 +14,7 @@
  #include "intel_psr.h"
  #include "intel_vrr.h"
  #include "intel_vrr_regs.h"
+#include "intel_dmc_regs.h"

This is already added in patch#5, so drop this.


Regards,

Ankit

  #include "skl_prefill.h"
  #include "skl_watermark.h"

@@ -612,6 +613,20 @@ void intel_vrr_set_transcoder_timings(const struct intel_crtc_state *crtc_state)

                               EMP_AS_SDP_DB_TL(crtc_state->vrr.vsync_start));
  }

+void

+intel_vrr_dcb_increment_flip_count(struct intel_crtc_state *crtc_state,
+                                  struct intel_crtc *crtc)
+{
+       struct intel_display *display = to_intel_display(crtc_state);
+       enum pipe pipe = crtc->pipe;
+
+       if (!crtc_state->vrr.dc_balance.enable)
+               return;
+
+       intel_de_write(display, PIPEDMC_DCB_FLIP_COUNT(pipe),
+                      ++crtc->dc_balance.flip_count);
+}
+
  void intel_vrr_send_push(struct intel_dsb *dsb,
                         const struct intel_crtc_state *crtc_state)
  {
diff --git a/drivers/gpu/drm/i915/display/intel_vrr.h 
b/drivers/gpu/drm/i915/display/intel_vrr.h
index 66fb9ad846f2..eebc7be309db 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.h
+++ b/drivers/gpu/drm/i915/display/intel_vrr.h
@@ -14,6 +14,7 @@ struct intel_connector;
  struct intel_crtc_state;
  struct intel_dsb;
  struct intel_display;
+struct intel_crtc;

bool intel_vrr_is_capable(struct intel_connector *connector);

  bool intel_vrr_is_in_range(struct intel_connector *connector, int vrefresh);
@@ -39,6 +40,8 @@ bool intel_vrr_is_fixed_rr(const struct intel_crtc_state 
*crtc_state);
  void intel_vrr_transcoder_enable(const struct intel_crtc_state *crtc_state);
  void intel_vrr_transcoder_disable(const struct intel_crtc_state *crtc_state);
  void intel_vrr_set_fixed_rr_timings(const struct intel_crtc_state 
*crtc_state);
+void intel_vrr_dcb_increment_flip_count(struct intel_crtc_state *crtc_state,
+                                       struct intel_crtc *crtc);
  bool intel_vrr_always_use_vrr_tg(struct intel_display *display);
  int intel_vrr_safe_window_start(const struct intel_crtc_state *crtc_state);
  int intel_vrr_vmin_safe_window_end(const struct intel_crtc_state *crtc_state);