drm/edid: Fix sync polarity for secondary GTF curve

Signed-off-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_modes.c

@@ -452,7 +452,10 @@ drm_gtf_mode_complex(struct drm_device *dev, int hdisplay, int vdisplay,
 	}
 
 	drm_mode_set_name(drm_mode);
-	drm_mode->flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC;
+	if (GTF_M == 600 && GTF_2C == 80 && GTF_K == 128 && GTF_2J == 40)
+		drm_mode->flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC;
+	else
+		drm_mode->flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC;
 
 	return drm_mode;
 }