From f6c8dbe6e50c6e5121d7b6644718207daa008221 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Sat, 15 Jun 2013 07:28:28 -0400 Subject: n_tty: Encapsulate minimum_to_wake within N_TTY minimum_to_wake is unique to N_TTY processing, and belongs in per-ldisc data. Add the ldisc method, ldisc_ops::fasync(), to notify line disciplines when signal-driven I/O is enabled or disabled. When enabled for N_TTY (by fcntl(F_SETFL, O_ASYNC)), blocking reader/polls will be woken for any readable input. When disabled, blocking reader/polls are not woken until the read buffer is full. Canonical mode (L_ICANON(tty), n_tty_data::icanon) is not affected by the minimum_to_wake setting. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 1 - include/linux/tty_ldisc.h | 6 ++++++ 2 files changed, 6 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/tty.h b/include/linux/tty.h index 82ab69bc9b79..01ac30efd6a6 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -272,7 +272,6 @@ struct tty_struct { #define N_TTY_BUF_SIZE 4096 unsigned char closing:1; - unsigned short minimum_to_wake; unsigned char *write_buf; int write_cnt; /* If the tty has a pending do_SAK, queue it here - akpm */ diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h index 7b24bbd85ea8..a1b048999821 100644 --- a/include/linux/tty_ldisc.h +++ b/include/linux/tty_ldisc.h @@ -100,6 +100,11 @@ * seek to perform this action quickly but should wait until * any pending driver I/O is completed. * + * void (*fasync)(struct tty_struct *, int on) + * + * Notify line discipline when signal-driven I/O is enabled or + * disabled. + * * void (*dcd_change)(struct tty_struct *tty, unsigned int status) * * Tells the discipline that the DCD pin has changed its status. @@ -189,6 +194,7 @@ struct tty_ldisc_ops { char *fp, int count); void (*write_wakeup)(struct tty_struct *); void (*dcd_change)(struct tty_struct *, unsigned int); + void (*fasync)(struct tty_struct *tty, int on); struct module *owner; -- cgit v1.2.3