diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index c784e77f610b..10943539bc7c 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -392,11 +392,16 @@ static u32 get_pr_alpm_as_sdp_transmission_time(const struct intel_crtc_state *c
  */
 static u32 intel_pr_as_sdp_skip_frames(struct intel_dp *intel_dp)
 {
+	struct intel_display *display = to_intel_display(intel_dp);
 	const struct drm_display_info *info =
 		&intel_dp->attached_connector->base.display_info;
 	int max_vrefresh = info->monitor_range.max_vfreq;
 	int min_vrefresh = info->monitor_range.min_vfreq;
 
+	/* Off by default; gated by the enable_periodic_assdp debugfs knob. */
+	if (!display->params.enable_periodic_assdp)
+		return 0;
+
 	if (min_vrefresh <= 0 || max_vrefresh <= min_vrefresh)
 		return 0;
 
diff --git a/drivers/gpu/drm/i915/display/intel_display_params.h b/drivers/gpu/drm/i915/display/intel_display_params.h
index b95ecf728daa..ba01aeaf8944 100644
--- a/drivers/gpu/drm/i915/display/intel_display_params.h
+++ b/drivers/gpu/drm/i915/display/intel_display_params.h
@@ -50,6 +50,11 @@ struct drm_printer;
 	param(bool, psr_safest_params, false, 0400) \
 	param(bool, enable_psr2_sel_fetch, true, 0400) \
 	param(int, enable_dmc_wl, -1, 0400) \
+	/*
+	 * Debugfs-only knob (per-device): no matching module_param is registered
+	 * in intel_display_params.c on purpose. Runtime-toggle via debugfs.
+	 */ \
+	param(bool, enable_periodic_assdp, false, 0600) \
 
 #define MEMBER(T, member, ...) T member;
 struct intel_display_params {