Commit 2ddce3fd authored by Ian Armstrong's avatar Ian Armstrong Committed by Linus Torvalds
Browse files

fbcon: only unbind from console if successfully registered

Attempting to unload a framebuffer module calls unregister_framebuffer()
which in turn gets fbcon to release it.  If fbcon has no framebuffers
linked to a console, it will also unbind itself from the console driver.
However, if fbcon never registered itself as a console driver, the unbind
will fail causing the framebuffer device entry to persist.  In most cases
this failure will result in an oops when attempting to access the now
non-existent device.

This patch ensures that the fbcon unbind request will succeed even if a
bind was never done.  It tracks if a successful bind ever occurred & will
only attempt to unbind if needed.  If there never was a bind, it simply
returns with no error.
Signed-off-by: default avatarIan Armstrong <>
Cc: Krzysztof Helt <>
Cc: <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent a690606d
......@@ -114,6 +114,7 @@ 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 fbcon_has_console_bind;
static int map_override;
......@@ -544,6 +545,8 @@ static int fbcon_takeover(int show_logo)
con2fb_map[i] = -1;
info_idx = -1;
} else {
fbcon_has_console_bind = 1;
return err;
......@@ -2949,6 +2952,10 @@ static int fbcon_unbind(void)
ret = unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
if (!ret)
fbcon_has_console_bind = 0;
return ret;
......@@ -2962,6 +2969,9 @@ static int fbcon_fb_unbind(int idx)
int i, new_idx = -1, ret = 0;
if (!fbcon_has_console_bind)
return 0;
for (i = first_fb_vc; i <= last_fb_vc; i++) {
if (con2fb_map[i] != idx &&
con2fb_map[i] != -1) {
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