[src/trunk]: src/sys/external/bsd/drm2/drm drmfb: Rework console detection an...

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

details:   https://anonhg.NetBSD.org/src/rev/74fe6e01e4ef
branches:  trunk
changeset: 369804:74fe6e01e4ef
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Sep 01 17:54:47 2022 +0000

description:
drmfb: Rework console detection and takeover.

While here, simplify logic by removing an unreachable error branch so
we never have to contemplate unwinding claiming of the console.

diffstat:

 sys/external/bsd/drm2/drm/drmfb.c |  71 +++++++++++++++-----------------------
 1 files changed, 29 insertions(+), 42 deletions(-)

diffs (114 lines):

diff -r af45447e68df -r 74fe6e01e4ef sys/external/bsd/drm2/drm/drmfb.c
--- a/sys/external/bsd/drm2/drm/drmfb.c Thu Sep 01 16:28:08 2022 +0000
+++ b/sys/external/bsd/drm2/drm/drmfb.c Thu Sep 01 17:54:47 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: drmfb.c,v 1.15 2022/09/01 12:01:36 riastradh Exp $     */
+/*     $NetBSD: drmfb.c,v 1.16 2022/09/01 17:54:47 riastradh Exp $     */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: drmfb.c,v 1.15 2022/09/01 12:01:36 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: drmfb.c,v 1.16 2022/09/01 17:54:47 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "vga.h"
@@ -94,9 +94,8 @@
 #endif
        static const struct genfb_ops zero_genfb_ops;
        struct genfb_ops genfb_ops = zero_genfb_ops;
-       enum { CONS_VGA, CONS_GENFB, CONS_NONE } what_was_cons;
        bool is_console;
-       int error;
+       int error __diagused;
 
        /* genfb requires this.  */
        KASSERTMSG((void *)&sc->sc_genfb == device_private(da->da_dev),
@@ -116,29 +115,35 @@
        prop_dictionary_set_uint64(dict, "mode_callback",
            (uint64_t)(uintptr_t)&drmfb_genfb_mode_callback);
 
+       /*
+        * Determine whether MD firmware logic has set the console to
+        * go through this device.
+        */
        if (prop_dictionary_get_bool(pdict, "is_console", &is_console)) {
-               what_was_cons = CONS_NONE;
-               prop_dictionary_set_bool(dict, "is_console", is_console);
+               /* nothing */
+       } else if (genfb_is_console() && genfb_is_enabled()) {
+               is_console = true;
        } else {
-               /* XXX Whattakludge!  */
+               is_console = false;
+       }
+
 #if NVGA > 0
-               if ((da->da_params->dp_is_vga_console != NULL) &&
-                   (*da->da_params->dp_is_vga_console)(dev)) {
-                       what_was_cons = CONS_VGA;
-                       prop_dictionary_set_bool(dict, "is_console", true);
-                       vga_cndetach();
-                       if (da->da_params->dp_disable_vga)
-                               (*da->da_params->dp_disable_vga)(dev);
-               } else
+       /*
+        * Whether or not we were told to be the console, if the
+        * console was configured to go through a vga resource that we
+        * now own and that vga(4) is not going to take over, kick out
+        * the vga console before we take over as genfb console.
+        */
+       if ((da->da_params->dp_is_vga_console != NULL) &&
+           (*da->da_params->dp_is_vga_console)(dev)) {
+               vga_cndetach();
+               if (da->da_params->dp_disable_vga)
+                       (*da->da_params->dp_disable_vga)(dev);
+               is_console = true;
+       }
 #endif
-               if (genfb_is_console() && genfb_is_enabled()) {
-                       what_was_cons = CONS_GENFB;
-                       prop_dictionary_set_bool(dict, "is_console", true);
-               } else {
-                       what_was_cons = CONS_NONE;
-                       prop_dictionary_set_bool(dict, "is_console", false);
-               }
-       }
+
+       prop_dictionary_set_bool(dict, "is_console", is_console);
 
        /* Make the first EDID we find available to wsfb */
        drm_connector_list_iter_begin(da->da_fb_helper->dev, &conn_iter);
@@ -162,28 +167,10 @@
        KERNEL_LOCK(1, NULL);
        error = genfb_attach(&sc->sc_genfb, &genfb_ops);
        KERNEL_UNLOCK_ONE(NULL);
-       if (error) {
-               aprint_error_dev(sc->sc_da.da_dev,
-                   "failed to attach genfb: %d\n", error);
-               goto fail0;
-       }
+       KASSERTMSG(error == 0, "genfb_attach failed, error=%d", error);
 
        /* Success!  */
        return 0;
-
-fail0: KASSERT(error);
-       /* XXX Restore console...  */
-       switch (what_was_cons) {
-       case CONS_VGA:
-               break;
-       case CONS_GENFB:
-               break;
-       case CONS_NONE:
-               break;
-       default:
-               break;
-       }
-       return error;
 }
 
 int