From: Ankit Nautiyal Date: Fri, 24 Apr 2026 09:09:41 +0000 (+0530) Subject: drm/i915/dp: Add a helper to decide if AS SDP can be used X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=e2b3b2e8fa9831d54d6638c3e7e3d5cc1ea4a493;p=thirdparty%2Fkernel%2Flinux.git drm/i915/dp: Add a helper to decide if AS SDP can be used Add a helper that determines whether AS SDP can be used for the current DP configuration. For now this is true only when the sink supports AS SDP and VRR is enabled, but more conditions may be added later. v2: - Rename to intel_dp_needs_as_sdp(). (Ville) - Add a #FIXME documenting non-atomic of DP SDP updates. (Ville) Signed-off-by: Ankit Nautiyal Reviewed-by: Ville Syrjälä Link: https://patch.msgid.link/20260424090942.3060291-3-ankit.k.nautiyal@intel.com --- diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 8631df908b07..8f2cd603f52a 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -3168,6 +3168,15 @@ static void intel_dp_compute_vsc_colorimetry(const struct intel_crtc_state *crtc vsc->content_type = DP_CONTENT_TYPE_NOT_DEFINED; } +static bool intel_dp_needs_as_sdp(struct intel_dp *intel_dp, + struct intel_crtc_state *crtc_state) +{ + if (!intel_dp->as_sdp_supported) + return false; + + return crtc_state->vrr.enable; +} + static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp, struct intel_crtc_state *crtc_state) { @@ -3175,7 +3184,12 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp, const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode; - if (!crtc_state->vrr.enable || !intel_dp->as_sdp_supported) + /* + * #FIXME: SDP/infoframe updates aren’t truly atomic, and with the new + * cdclk->tc clock crossing we may transiently send a corrupted packet + * if the update lands mid‑transmission. + */ + if (!intel_dp_needs_as_sdp(intel_dp, crtc_state)) return; crtc_state->infoframes.enable |= intel_hdmi_infoframe_enable(DP_SDP_ADAPTIVE_SYNC);