[PATCH 2/2] tty: metag_da: avoid getting tty kref in dashtty_timer()

James Hogan
2013-02-06T14:45:52Z

Getting the tty kref in dashtty_timer() is no longer necessary since it
isn't needed in fetch_data() any longer (due to changes which make the
tty flip functions refer to tty_ports instead of tty_structs), so just
pass around a channel number instead.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/metag_da.c | 31 ++++++++++++++-----------------
1 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/metag_da.c b/drivers/tty/metag_da.c
index fc2a36b..0e88862 100644
--- a/drivers/tty/metag_da.c
+++ b/drivers/tty/metag_da.c
@@ -147,9 +147,8 @@ static int chancall(int in_bios_function, int in_channel,
/*
* Attempts to fetch count bytes from channel and returns actual count.
*/
-static int fetch_data(struct tty_struct *tty)
+static int fetch_data(unsigned int channel)
{
- unsigned int channel = tty->index;
struct dashtty_port *dport = &dashtty_ports[channel];
int received = 0;

@@ -180,31 +179,31 @@ unlock:
}

/**
- * find_channel_to_poll() - Returns kref to the next channel tty to poll.
- * Returns: The TTY of the next channel to poll, or NULL if no TTY needs
- * polling. Release with tty_kref_put().
+ * find_channel_to_poll() - Returns number of the next channel to poll.
+ * Returns: The number of the next channel to poll, or -1 if none need
+ * polling.
*/
-static struct tty_struct *find_channel_to_poll(void)
+static int find_channel_to_poll(void)
{
static int last_polled_channel;
int last = last_polled_channel;
int chan;
- struct tty_struct *tty = NULL;
+ struct dashtty_port *dport;

for (chan = last + 1; ; ++chan) {
if (chan >= NUM_TTY_CHANNELS)
chan = 0;

- tty = tty_port_tty_get(&dashtty_ports[chan].port);
- if (tty) {
+ dport = &dashtty_ports[chan];
+ if (dport->rx_buf) {
last_polled_channel = chan;
- return tty;
+ return chan;
}

if (chan == last)
break;
}
- return tty;
+ return -1;
}

/**
@@ -302,19 +301,17 @@ static int put_data(void *arg)
*/
static void dashtty_timer(unsigned long ignored)
{
- struct tty_struct *tty;
+ int channel;

/* If there are no ports open do nothing and don't poll again. */
if (!atomic_read(&num_channels_need_poll))
return;

- tty = find_channel_to_poll();
+ channel = find_channel_to_poll();

/* Did we find a channel to poll? */
- if (tty) {
- fetch_data(tty);
- tty_kref_put(tty);
- }
+ if (channel >= 0)
+ fetch_data(channel);

mod_timer_pinned(&poll_timer, jiffies + DA_TTY_POLL);
}
--
1.7.7.6