Re: [PATCH v9 08/17] drm/i915/vrr: Add function to reset DC balance accumulated params

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 11/27/2025 2:46 PM, Mitul Golani wrote:
> Add function which resets all accumulated DC Balance parameters
> whenever adaptive mode of VRR goes off. This helps to give a
> fresh start when VRR is re-enabled.
>
> --v2:
> - Typo, change crtc_state to old_crtc_state. (Ankit)
>
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>


> ---
>   drivers/gpu/drm/i915/display/intel_display.c |  1 +
>   drivers/gpu/drm/i915/display/intel_vrr.c     | 13 +++++++++++++
>   drivers/gpu/drm/i915/display/intel_vrr.h     |  3 +++
>   3 files changed, 17 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index db4f84cb8762..d41ab965c013 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -1158,6 +1158,7 @@ static void intel_pre_plane_update(struct intel_atomic_state *state,
>   
>   	if (intel_crtc_vrr_disabling(state, crtc)) {
>   		intel_vrr_disable(old_crtc_state);
> +		intel_vrr_dcb_reset(old_crtc_state, crtc);
>   		intel_crtc_update_active_timings(old_crtc_state, false);
>   	}
>   
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index 45e632e8a981..ff65c1167e1b 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -632,6 +632,19 @@ 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_reset(const struct intel_crtc_state *old_crtc_state,
> +		    struct intel_crtc *crtc)
> +{
> +	struct intel_display *display = to_intel_display(old_crtc_state);
> +	enum pipe pipe = crtc->pipe;
> +
> +	if (!old_crtc_state->vrr.dc_balance.enable)
> +		return;
> +
> +	intel_de_write(display, PIPEDMC_DCB_BALANCE_RESET(pipe), 0);
> +}
> +
>   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..d40ed5504180 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.h
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.h
> @@ -11,6 +11,7 @@
>   struct drm_connector_state;
>   struct intel_atomic_state;
>   struct intel_connector;
> +struct intel_crtc;
>   struct intel_crtc_state;
>   struct intel_dsb;
>   struct intel_display;
> @@ -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_reset(const struct intel_crtc_state *old_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);