tty: Only perform flip buffer flush from tty_buffer_flush()
Now that dropping the buffer lock is not necessary (as result of
converting the spin lock to a mutex), the flip buffer flush no
longer needs to be handled by the buffer work.
Simply signal a flush is required; the buffer work will exit the
i/o loop, which allows tty_buffer_flush() to proceed.
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 c3c606c..39cae61 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -189,19 +189,11 @@
struct tty_port *port = tty->port;
struct tty_bufhead *buf = &port->buf;
- mutex_lock(&buf->flush_mutex);
- /* If the data is being pushed to the tty layer then we can't
- process it here. Instead set a flag and the flush_to_ldisc
- path will process the flush request before it exits */
- if (test_bit(TTYP_FLUSHING, &port->iflags)) {
- set_bit(TTYP_FLUSHPENDING, &port->iflags);
- mutex_unlock(&buf->flush_mutex);
- wait_event(tty->read_wait,
- test_bit(TTYP_FLUSHPENDING, &port->iflags) == 0);
- return;
- }
+ set_bit(TTYP_FLUSHPENDING, &port->iflags);
+ mutex_lock(&buf->flush_mutex);
__tty_buffer_flush(port);
+ clear_bit(TTYP_FLUSHPENDING, &port->iflags);
mutex_unlock(&buf->flush_mutex);
}
@@ -429,39 +421,26 @@
mutex_lock(&buf->flush_mutex);
- if (!test_and_set_bit(TTYP_FLUSHING, &port->iflags)) {
- while (1) {
- struct tty_buffer *head = buf->head;
- int count;
+ while (1) {
+ struct tty_buffer *head = buf->head;
+ int count;
- count = head->commit - head->read;
- if (!count) {
- if (head->next == NULL)
- break;
- buf->head = head->next;
- tty_buffer_free(port, head);
- continue;
- }
+ /* Ldisc or user is trying to flush the buffers. */
+ if (test_bit(TTYP_FLUSHPENDING, &port->iflags))
+ break;
- mutex_unlock(&buf->flush_mutex);
-
- count = receive_buf(tty, head, count);
-
- mutex_lock(&buf->flush_mutex);
-
- /* Ldisc or user is trying to flush the buffers.
- We may have a deferred request to flush the
- input buffer, if so pull the chain under the lock
- and empty the queue */
- if (test_bit(TTYP_FLUSHPENDING, &port->iflags)) {
- __tty_buffer_flush(port);
- clear_bit(TTYP_FLUSHPENDING, &port->iflags);
- wake_up(&tty->read_wait);
+ count = head->commit - head->read;
+ if (!count) {
+ if (head->next == NULL)
break;
- } else if (!count)
- break;
+ buf->head = head->next;
+ tty_buffer_free(port, head);
+ continue;
}
- clear_bit(TTYP_FLUSHING, &port->iflags);
+
+ count = receive_buf(tty, head, count);
+ if (!count)
+ break;
}
mutex_unlock(&buf->flush_mutex);