diff -r 8f1fc1b74860 sys/dev/acpi/acpi_pci.h
--- a/sys/dev/acpi/acpi_pci.h	Fri Jan 17 04:11:33 2025 +0000
+++ b/sys/dev/acpi/acpi_pci.h	Mon Jan 20 17:16:22 2025 +0000
@@ -31,6 +31,13 @@
 #ifndef _SYS_DEV_ACPI_ACPI_PCI_H
 #define _SYS_DEV_ACPI_ACPI_PCI_H
 
+#include <sys/types.h>
+
+#include <dev/acpi/acpica.h>
+#include <dev/pci/pcivar.h>
+
+struct acpi_devnode;
+
 ACPI_STATUS		 acpi_pcidev_scan(struct acpi_devnode *);
 ACPI_STATUS		 acpi_pcidev_pciroot_bus(ACPI_HANDLE, uint16_t *);
 ACPI_STATUS		 acpi_pcidev_ppb_downbus(pci_chipset_tag_t,
diff -r 8f1fc1b74860 sys/external/bsd/drm2/dist/drm/i915/display/intel_opregion.c
--- a/sys/external/bsd/drm2/dist/drm/i915/display/intel_opregion.c	Fri Jan 17 04:11:33 2025 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/display/intel_opregion.c	Mon Jan 20 17:16:22 2025 +0000
@@ -32,6 +32,7 @@
 
 #ifdef __NetBSD__
 #include <dev/acpi/acpi_display.h>
+#include <dev/acpi/acpi_pci.h>
 #endif
 
 #include <linux/acpi.h>
@@ -459,7 +460,18 @@ static u32 asle_set_backlight(struct drm
 
 	DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
 
-#ifndef __NetBSD__ /* XXX backlight */
+#ifdef __NetBSD__
+	const struct pci_attach_args *const pa = &dev->pdev->pd_pa;
+	struct acpi_devnode *const node =
+	    acpi_pcidev_find(pci_get_segment(pa->pa_pc),
+		pa->pa_bus, pa->pa_device, pa->pa_function);
+	if (node != NULL && node->ad_device != NULL) {
+		/* XXX device_acquire, device_release */
+		DRM_DEBUG_KMS("deferring backlight to %s\n",
+		    device_xname(node->ad_device));
+		return 0;
+	}
+#else
 	if (acpi_video_get_backlight_type() == acpi_backlight_native) {
 		DRM_DEBUG_KMS("opregion backlight request ignored\n");
 		return 0;