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-rw-r--r--drivers/tty/Kconfig14
-rw-r--r--drivers/tty/Makefile3
-rw-r--r--drivers/tty/ttynull.c18
-rw-r--r--include/linux/console.h3
-rw-r--r--init/main.c10
5 files changed, 18 insertions, 30 deletions
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index 47a6e42f0d04..e15cd6b5bb99 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -401,6 +401,20 @@ config MIPS_EJTAG_FDC_KGDB_CHAN
help
FDC channel number to use for KGDB.
+config NULL_TTY
+ tristate "NULL TTY driver"
+ help
+ Say Y here if you want a NULL TTY which simply discards messages.
+
+ This is useful to allow userspace applications which expect a console
+ device to work without modifications even when no console is
+ available or desired.
+
+ In order to use this driver, you should redirect the console to this
+ TTY, or boot the kernel with console=ttynull.
+
+ If unsure, say N.
+
config TRACE_ROUTER
tristate "Trace data router for MIPI P1149.7 cJTAG standard"
depends on TRACE_SINK
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index 3c1c5a9240a7..b3ccae932660 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -2,7 +2,7 @@
obj-$(CONFIG_TTY) += tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o \
tty_buffer.o tty_port.o tty_mutex.o \
tty_ldsem.o tty_baudrate.o tty_jobctrl.o \
- n_null.o ttynull.o
+ n_null.o
obj-$(CONFIG_LEGACY_PTYS) += pty.o
obj-$(CONFIG_UNIX98_PTYS) += pty.o
obj-$(CONFIG_AUDIT) += tty_audit.o
@@ -25,6 +25,7 @@ obj-$(CONFIG_ISI) += isicom.o
obj-$(CONFIG_MOXA_INTELLIO) += moxa.o
obj-$(CONFIG_MOXA_SMARTIO) += mxser.o
obj-$(CONFIG_NOZOMI) += nozomi.o
+obj-$(CONFIG_NULL_TTY) += ttynull.o
obj-$(CONFIG_ROCKETPORT) += rocket.o
obj-$(CONFIG_SYNCLINK_GT) += synclink_gt.o
obj-$(CONFIG_PPC_EPAPR_HV_BYTECHAN) += ehv_bytechan.o
diff --git a/drivers/tty/ttynull.c b/drivers/tty/ttynull.c
index eced70ec54e1..17f05b7eb6d3 100644
--- a/drivers/tty/ttynull.c
+++ b/drivers/tty/ttynull.c
@@ -2,13 +2,6 @@
/*
* Copyright (C) 2019 Axis Communications AB
*
- * The console is useful for userspace applications which expect a console
- * device to work without modifications even when no console is available
- * or desired.
- *
- * In order to use this driver, you should redirect the console to this
- * TTY, or boot the kernel with console=ttynull.
- *
* Based on ttyprintk.c:
* Copyright (C) 2010 Samo Pogacnik
*/
@@ -66,17 +59,6 @@ static struct console ttynull_console = {
.device = ttynull_device,
};
-void __init register_ttynull_console(void)
-{
- if (!ttynull_driver)
- return;
-
- if (add_preferred_console(ttynull_console.name, 0, NULL))
- return;
-
- register_console(&ttynull_console);
-}
-
static int __init ttynull_init(void)
{
struct tty_driver *driver;
diff --git a/include/linux/console.h b/include/linux/console.h
index dbe78e8e2602..20874db50bc8 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -186,12 +186,9 @@ extern int braille_register_console(struct console *, int index,
extern int braille_unregister_console(struct console *);
#ifdef CONFIG_TTY
extern void console_sysfs_notify(void);
-extern void register_ttynull_console(void);
#else
static inline void console_sysfs_notify(void)
{ }
-static inline void register_ttynull_console(void)
-{ }
#endif
extern bool console_suspend_enabled;
diff --git a/init/main.c b/init/main.c
index 421640fca375..c68d784376ca 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1480,14 +1480,8 @@ void __init console_on_rootfs(void)
struct file *file = filp_open("/dev/console", O_RDWR, 0);
if (IS_ERR(file)) {
- pr_err("Warning: unable to open an initial console. Fallback to ttynull.\n");
- register_ttynull_console();
-
- file = filp_open("/dev/console", O_RDWR, 0);
- if (IS_ERR(file)) {
- pr_err("Warning: Failed to add ttynull console. No stdin, stdout, and stderr for the init process!\n");
- return;
- }
+ pr_err("Warning: unable to open an initial console.\n");
+ return;
}
init_dup(file);
init_dup(file);