TTY: switch tty_flip_buffer_push
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c
index a2a0c43..b403393 100644
--- a/drivers/staging/fwserial/fwserial.c
+++ b/drivers/staging/fwserial/fwserial.c
@@ -489,16 +489,11 @@
static void fwtty_emit_breaks(struct work_struct *work)
{
struct fwtty_port *port = to_port(to_delayed_work(work), emit_breaks);
- struct tty_struct *tty;
static const char buf[16];
unsigned long now = jiffies;
unsigned long elapsed = now - port->break_last;
int n, t, c, brk = 0;
- tty = tty_port_tty_get(&port->port);
- if (!tty)
- return;
-
/* generate breaks at the line rate (but at least 1) */
n = (elapsed * port->cps) / HZ + 1;
port->break_last = now;
@@ -514,9 +509,7 @@
if (c < t)
break;
}
- tty_flip_buffer_push(tty);
-
- tty_kref_put(tty);
+ tty_flip_buffer_push(&port->port);
if (port->mstatus & (UART_LSR_BI << 24))
schedule_delayed_work(&port->emit_breaks, FREQ_BREAKS);
@@ -530,10 +523,6 @@
struct buffered_rx *buf, *next;
int n, c = 0;
- tty = tty_port_tty_get(&port->port);
- if (!tty)
- return;
-
spin_lock_bh(&port->lock);
list_for_each_entry_safe(buf, next, &port->buf_list, list) {
n = tty_insert_flip_string_fixed_flag(&port->port, buf->data,
@@ -545,7 +534,11 @@
memmove(buf->data, buf->data + n, buf->n - n);
buf->n -= n;
}
- __fwtty_throttle(port, tty);
+ tty = tty_port_tty_get(&port->port);
+ if (tty) {
+ __fwtty_throttle(port, tty);
+ tty_kref_put(tty);
+ }
break;
} else {
list_del(&buf->list);
@@ -553,13 +546,11 @@
}
}
if (c > 0)
- tty_flip_buffer_push(tty);
+ tty_flip_buffer_push(&port->port);
if (list_empty(&port->buf_list))
clear_bit(BUFFERING_RX, &port->flags);
spin_unlock_bh(&port->lock);
-
- tty_kref_put(tty);
}
static int fwtty_buffer_rx(struct fwtty_port *port, unsigned char *d, size_t n)
@@ -594,10 +585,6 @@
unsigned lsr;
int err = 0;
- tty = tty_port_tty_get(&port->port);
- if (!tty)
- return -ENOENT;
-
fwtty_dbg(port, "%d", n);
profile_size_distrib(port->stats.reads, n);
@@ -634,16 +621,20 @@
c = tty_insert_flip_string_fixed_flag(&port->port, data,
TTY_NORMAL, n);
if (c > 0)
- tty_flip_buffer_push(tty);
+ tty_flip_buffer_push(&port->port);
n -= c;
if (n) {
/* start buffering and throttling */
n -= fwtty_buffer_rx(port, &data[c], n);
- spin_lock_bh(&port->lock);
- __fwtty_throttle(port, tty);
- spin_unlock_bh(&port->lock);
+ tty = tty_port_tty_get(&port->port);
+ if (tty) {
+ spin_lock_bh(&port->lock);
+ __fwtty_throttle(port, tty);
+ spin_unlock_bh(&port->lock);
+ tty_kref_put(tty);
+ }
}
} else
n -= fwtty_buffer_rx(port, data, n);
@@ -654,8 +645,6 @@
}
out:
- tty_kref_put(tty);
-
port->icount.rx += len;
port->stats.lost += n;
return err;