tty: Use non-atomic state to signal flip buffer flush pending
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>
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 39cae61..fb042b9 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -189,11 +189,11 @@
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 @@
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 @@
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);
}