drm/i915/dp: Check if guardband can accommodate sdp latencies

Check if guardband is sufficient for all DP SDP latencies.
If its not, fail .compute_config_late().

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lore.kernel.org/r/20251017123504.2247954-4-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 9441ef6852005d607c0504b21e07246a1a976b53..b0aeb6c2de86ca268f32fc8055e7c3e8df0af72d 100644 (file)
--- 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"
 
@@ -6992,14 +6993,35 @@ 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);
+       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;
 }