Only look for acpi tables if acpi(4) attached. Fixes radeondrm(4) crash

on arm64 when using a device tree.

diff --git a/sys/dev/pci/drm/drm_linux.c b/sys/dev/pci/drm/drm_linux.c
index f71aab5..635cf7f 100644 (file)
--- a/sys/dev/pci/drm/drm_linux.c
+++ b/sys/dev/pci/drm/drm_linux.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: drm_linux.c,v 1.31 2018/08/25 18:42:43 kettenis Exp $ */
+/*     $OpenBSD: drm_linux.c,v 1.32 2018/09/11 20:25:58 kettenis Exp $ */
 /*
  * Copyright (c) 2013 Jonathan Gray <jsg@openbsd.org>
  * Copyright (c) 2015, 2016 Mark Kettenis <kettenis@openbsd.org>
@@ -747,6 +747,9 @@ acpi_get_table_with_size(const char *sig, int instance,
 
        KASSERT(instance == 1);
 
+       if (sc == NULL)
+               return AE_NOT_FOUND;
+
        SIMPLEQ_FOREACH(entry, &sc->sc_tables, q_next) {
                if (memcmp(entry->q_table, sig, strlen(sig)) == 0) {
                        *hdr = entry->q_table;