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 --- drivers/serial/crisv10.c | 6 ------ drivers/serial/jsm/jsm_tty.c | 7 ------- 2 files changed, 13 deletions(-) (limited to 'drivers/serial') diff --git a/drivers/serial/crisv10.c b/drivers/serial/crisv10.c index 89700141f87e..5cacc5e74a92 100644 --- a/drivers/serial/crisv10.c +++ b/drivers/serial/crisv10.c @@ -2573,12 +2573,6 @@ static void flush_to_flip_buffer(struct e100_serial *info) DFLIP( if (1) { - - if (test_bit(TTY_DONT_FLIP, &tty->flags)) { - DEBUG_LOG(info->line, "*** TTY_DONT_FLIP set flip.count %i ***\n", tty->flip.count); - DEBUG_LOG(info->line, "*** recv_cnt %i\n", info->recv_cnt); - } else { - } DEBUG_LOG(info->line, "*** rxtot %i\n", info->icount.rx); DEBUG_LOG(info->line, "ldisc %lu\n", tty->ldisc.chars_in_buffer(tty)); DEBUG_LOG(info->line, "room %lu\n", tty->ldisc.receive_room(tty)); diff --git a/drivers/serial/jsm/jsm_tty.c b/drivers/serial/jsm/jsm_tty.c index 7d823705193c..f8262e6ad8d3 100644 --- a/drivers/serial/jsm/jsm_tty.c +++ b/drivers/serial/jsm/jsm_tty.c @@ -588,13 +588,6 @@ void jsm_input(struct jsm_channel *ch) len = min(len, (N_TTY_BUF_SIZE - 1) - tp->read_cnt); ld = tty_ldisc_ref(tp); - /* - * If the DONT_FLIP flag is on, don't flush our buffer, and act - * like the ld doesn't have any space to put the data right now. - */ - if (test_bit(TTY_DONT_FLIP, &tp->flags)) - len = 0; - /* * If we were unable to get a reference to the ld, * don't flush our buffer, and act like the ld doesn't -- cgit v1.2.3