From 817d6d3bceaf34c99f5343820f9b9e6021f0655c Mon Sep 17 00:00:00 2001 From: Paul Fulghum Date: Wed, 28 Jun 2006 04:26:47 -0700 Subject: [PATCH] remove TTY_DONT_FLIP Remove TTY_DONT_FLIP tty flag. This flag was introduced in 2.1.X kernels to prevent the N_TTY line discipline functions read_chan() and n_tty_receive_buf() from running at the same time. 2.2.15 introduced tty->read_lock to protect access to the N_TTY read buffer, which is the only state requiring protection between these two functions. The current TTY_DONT_FLIP implementation is broken for SMP, and is not universally honored by drivers that send data directly to the line discipline receive_buf function. Because TTY_DONT_FLIP is not necessary, is broken in implementation, and is not universally honored, it is removed. Signed-off-by: Paul Fulghum Cc: Alan Cox Cc: Theodore Ts'o Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/tty.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index cb35ca50a0a6..341cc4552c00 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -259,7 +259,6 @@ struct tty_struct { #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ #define TTY_PUSH 6 /* n_tty private */ #define TTY_CLOSING 7 /* ->close() in progress */ -#define TTY_DONT_FLIP 8 /* Defer buffer flip */ #define TTY_LDISC 9 /* Line discipline attached */ #define TTY_HW_COOK_OUT 14 /* Hardware can do output cooking */ #define TTY_HW_COOK_IN 15 /* Hardware can do input cooking */ -- cgit v1.2.3 From 33b37a33c242542fac2980b8ccd90977388b7a8d Mon Sep 17 00:00:00 2001 From: Paul Fulghum Date: Wed, 28 Jun 2006 04:26:49 -0700 Subject: [PATCH] remove active field from tty buffer structure Remove 'active' field from tty buffer structure. This was added in 2.6.16 as part of a patch to make the new tty buffering SMP safe. This field is unnecessary with the more intelligently written flush_to_ldisc that adds receive_room handling. Removing this field reverts to simpler logic where the tail buffer is always the 'active' buffer, which should not be freed by flush_to_ldisc. (active == buffer being filled with new data) The result is simpler, smaller, and faster tty buffer code. Signed-off-by: Paul Fulghum Cc: Alan Cox Cc: Theodore Ts'o Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/tty.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 341cc4552c00..b3b807e4b050 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -57,7 +57,6 @@ struct tty_buffer { unsigned char *flag_buf_ptr; int used; int size; - int active; int commit; int read; /* Data points here */ -- cgit v1.2.3