Messages in this thread Patch in this message | | | From | Alexey Dobriyan <> | Subject | [PATCH 1/2] Introduce tty_unregister_ldisc() | Date | Tue, 31 May 2005 23:56:00 +0400 |
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It's a bit strange to see tty_register_ldisc() call in modules' exit functions.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> ---
Documentation/tty.txt | 2 +- drivers/char/tty_io.c | 35 ++++++++++++++++++++++++----------- include/linux/tty.h | 1 + 3 files changed, 26 insertions(+), 12 deletions(-)
diff -uprN linux-tty_register_ldisc_000/Documentation/tty.txt linux-tty_register_ldisc_001/Documentation/tty.txt --- linux-tty_register_ldisc_000/Documentation/tty.txt 2005-05-31 20:12:47.000000000 +0400 +++ linux-tty_register_ldisc_001/Documentation/tty.txt 2005-05-31 23:19:32.000000000 +0400 @@ -22,7 +22,7 @@ copy of the structure. You must not re-r discipline even with the same data or your computer again will be eaten by demons. -In order to remove a line discipline call tty_register_ldisc passing NULL. +In order to remove a line discipline call tty_unregister_ldisc(). In ancient times this always worked. In modern times the function will return -EBUSY if the ldisc is currently in use. Since the ldisc referencing code manages the module counts this should not usually be a concern. diff -uprN linux-tty_register_ldisc_000/drivers/char/tty_io.c linux-tty_register_ldisc_001/drivers/char/tty_io.c --- linux-tty_register_ldisc_000/drivers/char/tty_io.c 2005-05-31 20:13:34.000000000 +0400 +++ linux-tty_register_ldisc_001/drivers/char/tty_io.c 2005-05-31 23:17:40.000000000 +0400 @@ -262,17 +262,10 @@ int tty_register_ldisc(int disc, struct return -EINVAL; spin_lock_irqsave(&tty_ldisc_lock, flags); - if (new_ldisc) { - tty_ldiscs[disc] = *new_ldisc; - tty_ldiscs[disc].num = disc; - tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; - tty_ldiscs[disc].refcount = 0; - } else { - if(tty_ldiscs[disc].refcount) - ret = -EBUSY; - else - tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; - } + tty_ldiscs[disc] = *new_ldisc; + tty_ldiscs[disc].num = disc; + tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; + tty_ldiscs[disc].refcount = 0; spin_unlock_irqrestore(&tty_ldisc_lock, flags); return ret; @@ -280,6 +273,26 @@ int tty_register_ldisc(int disc, struct EXPORT_SYMBOL(tty_register_ldisc); +int tty_unregister_ldisc(int disc) +{ + unsigned long flags; + int ret = 0; + + if (disc < N_TTY || disc >= NR_LDISCS) + return -EINVAL; + + spin_lock_irqsave(&tty_ldisc_lock, flags); + if (tty_ldiscs[disc].refcount) + ret = -EBUSY; + else + tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; + spin_unlock_irqrestore(&tty_ldisc_lock, flags); + + return ret; +} + +EXPORT_SYMBOL(tty_unregister_ldisc); + struct tty_ldisc *tty_ldisc_get(int disc) { unsigned long flags; diff -uprN linux-tty_register_ldisc_000/include/linux/tty.h linux-tty_register_ldisc_001/include/linux/tty.h --- linux-tty_register_ldisc_000/include/linux/tty.h 2005-05-31 20:15:51.000000000 +0400 +++ linux-tty_register_ldisc_001/include/linux/tty.h 2005-05-31 23:18:23.000000000 +0400 @@ -345,6 +345,7 @@ extern int tty_check_change(struct tty_s extern void stop_tty(struct tty_struct * tty); extern void start_tty(struct tty_struct * tty); extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc); +extern int tty_unregister_ldisc(int disc); extern int tty_register_driver(struct tty_driver *driver); extern int tty_unregister_driver(struct tty_driver *driver); extern void tty_register_device(struct tty_driver *driver, unsigned index, struct device *dev); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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