diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/tty_buffer.h | 1 | ||||
| -rw-r--r-- | include/linux/tty_ldisc.h | 14 | ||||
| -rw-r--r-- | include/linux/tty_port.h | 2 |
3 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/tty_buffer.h b/include/linux/tty_buffer.h index 3b9d77604291..1796648c2907 100644 --- a/include/linux/tty_buffer.h +++ b/include/linux/tty_buffer.h @@ -15,6 +15,7 @@ struct tty_buffer { int used; int size; int commit; + int lookahead; /* Lazy update on recv, can become less than "read" */ int read; int flags; /* Data points here */ diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h index e85002b56752..33678e1936f6 100644 --- a/include/linux/tty_ldisc.h +++ b/include/linux/tty_ldisc.h @@ -186,6 +186,18 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass, * indicate all data received is %TTY_NORMAL. If assigned, prefer this * function for automatic flow control. * + * @lookahead_buf: [DRV] ``void ()(struct tty_struct *tty, + * const unsigned char *cp, const char *fp, int count) + * + * This function is called by the low-level tty driver for characters + * not eaten by ->receive_buf() or ->receive_buf2(). It is useful for + * processing high-priority characters such as software flow-control + * characters that could otherwise get stuck into the intermediate + * buffer until tty has room to receive them. Ldisc must be able to + * handle later a ->receive_buf() or ->receive_buf2() call for the + * same characters (e.g. by skipping the actions for high-priority + * characters already handled by ->lookahead_buf()). + * * @owner: module containting this ldisc (for reference counting) * * This structure defines the interface between the tty line discipline @@ -229,6 +241,8 @@ struct tty_ldisc_ops { void (*dcd_change)(struct tty_struct *tty, unsigned int status); int (*receive_buf2)(struct tty_struct *tty, const unsigned char *cp, const char *fp, int count); + void (*lookahead_buf)(struct tty_struct *tty, const unsigned char *cp, + const unsigned char *fp, unsigned int count); struct module *owner; }; diff --git a/include/linux/tty_port.h b/include/linux/tty_port.h index 58e9619116b7..fa3c3bdaa234 100644 --- a/include/linux/tty_port.h +++ b/include/linux/tty_port.h @@ -40,6 +40,8 @@ struct tty_port_operations { struct tty_port_client_operations { int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t); + void (*lookahead_buf)(struct tty_port *port, const unsigned char *cp, + const unsigned char *fp, unsigned int count); void (*write_wakeup)(struct tty_port *port); }; |