From 4d18e6eff81e1d4d81d0942d5b7e96904b3b32df Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Fri, 22 Nov 2013 12:09:55 -0500 Subject: tty: Enable configurable tty flip buffer limit Allow driver to configure its maximum flip buffer memory consumption/limit. This is necessary for very-high speed line rates (in excess of 10MB/sec) because the flip buffers can be saturated before the line discipline has a chance to throttle the input. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_flip.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/tty_flip.h') diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h index 21ddd7d9ea1f..2da8bc2a5486 100644 --- a/include/linux/tty_flip.h +++ b/include/linux/tty_flip.h @@ -1,6 +1,7 @@ #ifndef _LINUX_TTY_FLIP_H #define _LINUX_TTY_FLIP_H +extern int tty_buffer_set_limit(struct tty_port *port, int limit); extern int tty_buffer_space_avail(struct tty_port *port); extern int tty_buffer_request_room(struct tty_port *port, size_t size); extern int tty_insert_flip_string_flags(struct tty_port *port, -- cgit v1.2.3 From 7e1e71d1546a28ea0ccc06320987e6c4ab2e1dbe Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Fri, 22 Nov 2013 12:09:57 -0500 Subject: tty: Remove tty_prepare_flip_string_flags() There is no in-tree user of tty_prepare_flip_string_flags(); remove. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_flip.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/tty_flip.h') diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h index 2da8bc2a5486..3f821e98af0f 100644 --- a/include/linux/tty_flip.h +++ b/include/linux/tty_flip.h @@ -10,8 +10,6 @@ extern int tty_insert_flip_string_fixed_flag(struct tty_port *port, const unsigned char *chars, char flag, size_t size); extern int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars, size_t size); -extern int tty_prepare_flip_string_flags(struct tty_port *port, - unsigned char **chars, char **flags, size_t size); extern void tty_flip_buffer_push(struct tty_port *port); void tty_schedule_flip(struct tty_port *port); -- cgit v1.2.3 From acc0f67f307f52f7aec1cffdc40a786c15dd21d9 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Mon, 9 Dec 2013 09:23:52 -0500 Subject: tty: Halve flip buffer GFP_ATOMIC memory consumption tty flip buffers use GFP_ATOMIC allocations for received data which is to be processed by the line discipline. For each byte received, an extra byte is used to indicate the error status of that byte. Instead, if the received data is error-free, encode the entire buffer without status bytes. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_flip.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'include/linux/tty_flip.h') diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h index 3f821e98af0f..c28dd523f96e 100644 --- a/include/linux/tty_flip.h +++ b/include/linux/tty_flip.h @@ -17,8 +17,12 @@ static inline int tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag) { struct tty_buffer *tb = port->buf.tail; - if (tb && tb->used < tb->size) { - *flag_buf_ptr(tb, tb->used) = flag; + int change; + + change = (tb->flags & TTYB_NORMAL) && (flag != TTY_NORMAL); + if (!change && tb->used < tb->size) { + if (~tb->flags & TTYB_NORMAL) + *flag_buf_ptr(tb, tb->used) = flag; *char_buf_ptr(tb, tb->used++) = ch; return 1; } -- cgit v1.2.3