fbcon: allow fbcon to use the primary display driver
Allow fbcon to select the primary display adapter using the
fb_is_primary_device() arch-specific helper. If a a primary adapter is
detected, fbcon will unbind the old adapter from the VT layer, then rebind
using the new adapter. This requires that bind_/unbind_con_driver() be made
public.
Because this feature may produce unexpected behavior (from the user's POV),
this must be explicitly enabled in Kconfig.
[akpm@linux-foundation.org: export unbind_con_driver]
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 349673d..8a389b3 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -2869,8 +2869,7 @@
static struct class *vtconsole_class;
-static int bind_con_driver(const struct consw *csw, int first, int last,
- int deflt)
+int bind_con_driver(const struct consw *csw, int first, int last, int deflt)
{
struct module *owner = csw->owner;
const char *desc = NULL;
@@ -2969,6 +2968,7 @@
module_put(owner);
return retval;
};
+EXPORT_SYMBOL(bind_con_driver);
#ifdef CONFIG_VT_HW_CONSOLE_BINDING
static int con_is_graphics(const struct consw *csw, int first, int last)
@@ -2987,8 +2987,7 @@
return retval;
}
-static int unbind_con_driver(const struct consw *csw, int first, int last,
- int deflt)
+int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
{
struct module *owner = csw->owner;
const struct consw *defcsw = NULL;
@@ -3073,6 +3072,7 @@
return retval;
}
+EXPORT_SYMBOL(unbind_con_driver);
static int vt_bind(struct con_driver *con)
{
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index d3b8a6b..160f55f 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -118,6 +118,26 @@
help
Low-level framebuffer-based console driver.
+config FRAMEBUFFER_CONSOLE_DETECT_PRIMARY
+ bool "Map the console to the primary display device"
+ depends on FRAMEBUFFER_CONSOLE && VT_HW_CONSOLE_BINDING
+ default n
+ ---help---
+ If this option is selected, the framebuffer console will
+ automatically select the primary display device (if the architecture
+ supports this feature). Otherwise, the framebuffer console will
+ always select the first framebuffer driver that is loaded. The latter
+ is the default behavior.
+
+ You can always override the automatic selection of the primary device
+ by using the fbcon=map: boot option.
+
+ To select this feature, "Support for binding and unbinding console
+ drivers", under "Device Drivers"->"Character Devices" must be set to
+ y.
+
+ If unsure, select n.
+
config FRAMEBUFFER_CONSOLE_ROTATION
bool "Framebuffer Console Rotation"
depends on FRAMEBUFFER_CONSOLE
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 7f4ed79..7ba21eb 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -75,6 +75,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/crc32.h> /* For counting font checksums */
+#include <asm/fb.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -125,6 +126,8 @@
static int last_fb_vc = MAX_NR_CONSOLES - 1;
static int fbcon_is_default = 1;
static int fbcon_has_exited;
+static int primary_device = -1;
+static int map_override;
/* font data */
static char fontname[40];
@@ -497,13 +500,17 @@
if (!strncmp(options, "map:", 4)) {
options += 4;
- if (*options)
+ if (*options) {
for (i = 0, j = 0; i < MAX_NR_CONSOLES; i++) {
if (!options[j])
j = 0;
con2fb_map_boot[i] =
(options[j++]-'0') % FB_MAX;
}
+
+ map_override = 1;
+ }
+
return 1;
}
@@ -3004,9 +3011,9 @@
return found;
}
-static int fbcon_fb_unregistered(int idx)
+static int fbcon_fb_unregistered(struct fb_info *info)
{
- int i;
+ int i, idx = info->node;
for (i = first_fb_vc; i <= last_fb_vc; i++) {
if (con2fb_map[i] == idx)
@@ -3034,12 +3041,70 @@
if (!num_registered_fb)
unregister_con_driver(&fb_con);
+
+ if (primary_device == idx)
+ primary_device = -1;
+
return 0;
}
-static int fbcon_fb_registered(int idx)
+#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY
+static int fbcon_select_primary(struct fb_info *info)
{
- int ret = 0, i;
+ int ret = 0;
+
+ if (!map_override && primary_device == -1 &&
+ fb_is_primary_device(info)) {
+ int i, err;
+
+ printk(KERN_INFO "fbcon: %s is primary device\n",
+ info->fix.id);
+ primary_device = info->node;
+
+ if (!con_is_bound(&fb_con))
+ goto done;
+
+ printk(KERN_INFO "fbcon: Unbinding old driver\n");
+ unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
+ fbcon_is_default);
+ info_idx = primary_device;
+
+ for (i = first_fb_vc; i <= last_fb_vc; i++) {
+ con2fb_map_boot[i] = primary_device;
+ con2fb_map[i] = primary_device;
+ }
+
+ printk(KERN_INFO "fbcon: Selecting new driver\n");
+ err = bind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
+ fbcon_is_default);
+
+ if (err) {
+ for (i = first_fb_vc; i <= last_fb_vc; i++)
+ con2fb_map[i] = -1;
+
+ info_idx = -1;
+ }
+
+ ret = 1;
+ }
+
+done:
+ return ret;
+}
+#else
+static inline int fbcon_select_primary(struct fb_info *info)
+{
+ return 0;
+}
+#endif /* CONFIG_FRAMEBUFFER_DETECT_PRIMARY */
+
+static int fbcon_fb_registered(struct fb_info *info)
+{
+ int ret = 0, i, idx = info->node;
+
+ if (fbcon_select_primary(info))
+ goto done;
+
if (info_idx == -1) {
for (i = first_fb_vc; i <= last_fb_vc; i++) {
@@ -3059,6 +3124,7 @@
}
}
+done:
return ret;
}
@@ -3182,10 +3248,10 @@
ret = fbcon_mode_deleted(info, mode);
break;
case FB_EVENT_FB_REGISTERED:
- ret = fbcon_fb_registered(info->node);
+ ret = fbcon_fb_registered(info);
break;
case FB_EVENT_FB_UNREGISTERED:
- ret = fbcon_fb_unregistered(info->node);
+ ret = fbcon_fb_unregistered(info);
break;
case FB_EVENT_SET_CONSOLE_MAP:
con2fb = event->data;