Commit 79ee2fbb authored by Ankit Nautiyal's avatar Ankit Nautiyal
Browse files

drm/i915/alpm: Allow LOBF only if window1 > alpm check_entry lines 



LOBF must be disabled if the number of lines within Window 1 is not greater
than ALPM_CTL[ALPM Entry Check]

v2: Consider the case where SCL is in the active region. (Ville)

Bspec:71041
Signed-off-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: default avatarMichał Grzelak <michal.grzelak@intel.com>
Link: https://patch.msgid.link/20260204050250.762718-3-ankit.k.nautiyal@intel.com
parent 32c471e8

drivers/gpu/drm/i915/display/intel_alpm.c

+22 −0
Original line number Diff line number Diff line
@@ -270,6 +270,23 @@ int intel_alpm_lobf_min_guardband(struct intel_crtc_state *crtc_state) 
	return first_sdp_position + waketime_in_lines + crtc_state->set_context_latency;

}



static bool intel_alpm_lobf_is_window1_sufficient(struct intel_crtc_state *crtc_state)

{

	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;

	int vblank = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay;

	int window1;



	/*

	 * LOBF must be disabled if the number of lines within Window 1 is not

	 * greater than ALPM_CTL[ALPM Entry Check]

	 */

	window1 = vblank - min(vblank,

			       crtc_state->vrr.guardband +

			       crtc_state->set_context_latency);



	return window1 > crtc_state->alpm_state.check_entry_lines;

}



void intel_alpm_lobf_compute_config_late(struct intel_dp *intel_dp,

					 struct intel_crtc_state *crtc_state)

{
@@ -279,6 +296,11 @@ void intel_alpm_lobf_compute_config_late(struct intel_dp *intel_dp, 
	if (!crtc_state->has_lobf)

		return;



	if (!intel_alpm_lobf_is_window1_sufficient(crtc_state)) {

		crtc_state->has_lobf = false;

		return;

	}



	/*

	 * LOBF can only be enabled if the time from the start of the SCL+Guardband

	 * window to the position of the first SDP is greater than the time it takes