[src/trunk]: src/sys/arch/powerpc/oea add a comment to explain why we defer w...

[macallan <macallan%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/92357e3abbdb
branches:  trunk
changeset: 359947:92357e3abbdb
user:      macallan <macallan%NetBSD.org@localhost>
date:      Fri Mar 02 14:45:23 2018 +0000

description:
add a comment to explain why we defer wsdisplay_preattach() in bridge mode

diffstat:

 sys/arch/powerpc/oea/ofw_rascons.c |  14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diffs (35 lines):

diff -r cfd78bd3a64e -r 92357e3abbdb sys/arch/powerpc/oea/ofw_rascons.c
--- a/sys/arch/powerpc/oea/ofw_rascons.c        Fri Mar 02 14:37:18 2018 +0000
+++ b/sys/arch/powerpc/oea/ofw_rascons.c        Fri Mar 02 14:45:23 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ofw_rascons.c,v 1.11 2018/03/02 14:37:18 macallan Exp $        */
+/*     $NetBSD: ofw_rascons.c,v 1.12 2018/03/02 14:45:23 macallan Exp $        */
 
 /*
  * Copyright (c) 1995, 1996 Carnegie-Mellon University.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ofw_rascons.c,v 1.11 2018/03/02 14:37:18 macallan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ofw_rascons.c,v 1.12 2018/03/02 14:45:23 macallan Exp $");
 
 #include "wsdisplay.h"
 
@@ -117,6 +117,16 @@
        rascons_stdscreen.textops = &ri->ri_ops;
        rascons_stdscreen.capabilities = ri->ri_caps;
 
+       /*
+        * XXX
+        * On some G5 models ( so far, 970FX but not 970MP ) we can't seem to
+        * access video memory in real mode, but a lot of code relies on rasops
+        * data structures being set up early so we can't just push the whole
+        * thing further down. Instead set things up but don't actually attach
+        * the console until later.
+        * This needs a better trigger but for now I can't reliably tell which
+        * exact models / CPUs / other hardware actually need it.
+        */
        if ((oeacpufeat & OEACPU_64_BRIDGE) != 0) {
                needs_finalize = 1;
        } else {