On Fri, Oct 17, 2025 at 10:32:00AM +0530, Ankit Nautiyal wrote: > Check if guardband is sufficient for all DP SDP latencies. > If its not, fail .compute_config_late(). > > Signed-off-by: Ankit Nautiyal <[email protected]> > --- > drivers/gpu/drm/i915/display/intel_dp.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c > b/drivers/gpu/drm/i915/display/intel_dp.c > index 3f2c319e3d6f..8ae99cee79d4 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -93,6 +93,7 @@ > #include "intel_psr.h" > #include "intel_quirks.h" > #include "intel_tc.h" > +#include "intel_vblank.h" > #include "intel_vdsc.h" > #include "intel_vrr.h" > > @@ -6980,14 +6981,35 @@ void intel_dp_mst_resume(struct intel_display > *display) > } > } > > +static > +int intel_dp_sdp_compute_config_late(struct intel_crtc_state *crtc_state) > +{ > + struct intel_display *display = to_intel_display(crtc_state); > + int guardband = intel_crtc_vblank_length(crtc_state);
In theory we might have enough legacy TG vblank but not VRR guardband (I suppose that can only happen on ICL/TGL due to the pipeline full limit) so I was pondering whether we might need to check both. But I think this is fine. We would just fail when trying to enable VRR in those cases, but without VRR enabled we can still light up th display. Reviewed-by: Ville Syrjälä <[email protected]> > + int min_sdp_guardband = intel_dp_sdp_min_guardband(crtc_state, false); > + > + if (guardband < min_sdp_guardband) { > + drm_dbg_kms(display->drm, "guardband %d < min sdp guardband > %d\n", > + guardband, min_sdp_guardband); > + return -EINVAL; > + } > + > + return 0; > +} > + > int intel_dp_compute_config_late(struct intel_encoder *encoder, > struct intel_crtc_state *crtc_state, > struct drm_connector_state *conn_state) > { > struct intel_dp *intel_dp = enc_to_intel_dp(encoder); > + int ret; > > intel_psr_compute_config_late(intel_dp, crtc_state); > > + ret = intel_dp_sdp_compute_config_late(crtc_state); > + if (ret) > + return ret; > + > return 0; > } > > -- > 2.45.2 -- Ville Syrjälä Intel
