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tty: Use non-atomic state to signal flip buffer flush pending

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Atomic bit ops are no longer required to indicate a flip buffer
flush is pending, as the flush_mutex is sufficient barrier.

Remove the unnecessary port .iflags field and localize flip buffer
state to struct tty_bufhead.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Hurley
2013-06-15 09:36:13 -04:00
committed by Greg Kroah-Hartman
parent 8c1fb49ba1
commit 0f56bd2f6a
2 changed files with 5 additions and 5 deletions
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7
drivers/tty/tty_buffer.c
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@@ -189,11 +189,11 @@ void tty_buffer_flush(struct tty_struct *tty)
struct tty_port *port = tty->port;
struct tty_bufhead *buf = &port->buf;
set_bit(TTYP_FLUSHPENDING, &port->iflags);
buf->flushpending = 1;
mutex_lock(&buf->flush_mutex);
__tty_buffer_flush(port);
clear_bit(TTYP_FLUSHPENDING, &port->iflags);
buf->flushpending = 0;
mutex_unlock(&buf->flush_mutex);
}
@@ -426,7 +426,7 @@ static void flush_to_ldisc(struct work_struct *work)
int count;
/* Ldisc or user is trying to flush the buffers. */
if (test_bit(TTYP_FLUSHPENDING, &port->iflags))
if (buf->flushpending)
break;
count = head->commit - head->read;
@@ -505,6 +505,7 @@ void tty_buffer_init(struct tty_port *port)
buf->tail = &buf->sentinel;
init_llist_head(&buf->free);
atomic_set(&buf->memory_used, 0);
buf->flushpending = 0;
INIT_WORK(&buf->work, flush_to_ldisc);
}