TTY: HVC, use count from tty_port

Now, count is used from tty_port and protected by tty_port->lock.

n_outbuf is left unprotected in hvc_hangup now, because there is no
point to hold any lock, since other uses are unprotected too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index 92b7f5d5441ff7998e577dc323757c582ef56165..6c45cbf3fc9163192981d63adcbcfa3fb211238e 100644 (file)
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -313,18 +313,18 @@ static int hvc_open(struct tty_struct *tty, struct file * filp)
        if (!(hp = hvc_get_by_index(tty->index)))
                return -ENODEV;
 
-       spin_lock_irqsave(&hp->lock, flags);
+       spin_lock_irqsave(&hp->port.lock, flags);
        /* Check and then increment for fast path open. */
-       if (hp->count++ > 0) {
+       if (hp->port.count++ > 0) {
+               spin_unlock_irqrestore(&hp->port.lock, flags);
+               /* FIXME why taking a reference here? */
                tty_kref_get(tty);
-               spin_unlock_irqrestore(&hp->lock, flags);
                hvc_kick();
                return 0;
        } /* else count == 0 */
+       spin_unlock_irqrestore(&hp->port.lock, flags);
 
        tty->driver_data = hp;
-       spin_unlock_irqrestore(&hp->lock, flags);
-
        tty_port_tty_set(&hp->port, tty);
 
        if (hp->ops->notifier_add)
@@ -367,10 +367,10 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
 
        hp = tty->driver_data;
 
-       spin_lock_irqsave(&hp->lock, flags);
+       spin_lock_irqsave(&hp->port.lock, flags);
 
-       if (--hp->count == 0) {
-               spin_unlock_irqrestore(&hp->lock, flags);
+       if (--hp->port.count == 0) {
+               spin_unlock_irqrestore(&hp->port.lock, flags);
                /* We are done with the tty pointer now. */
                tty_port_tty_set(&hp->port, NULL);
 
@@ -387,10 +387,10 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
                 */
                tty_wait_until_sent_from_close(tty, HVC_CLOSE_WAIT);
        } else {
-               if (hp->count < 0)
+               if (hp->port.count < 0)
                        printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
-                               hp->vtermno, hp->count);
-               spin_unlock_irqrestore(&hp->lock, flags);
+                               hp->vtermno, hp->port.count);
+               spin_unlock_irqrestore(&hp->port.lock, flags);
        }
 
        tty_kref_put(tty);
@@ -409,24 +409,25 @@ static void hvc_hangup(struct tty_struct *tty)
        /* cancel pending tty resize work */
        cancel_work_sync(&hp->tty_resize);
 
-       spin_lock_irqsave(&hp->lock, flags);
+       spin_lock_irqsave(&hp->port.lock, flags);
 
        /*
         * The N_TTY line discipline has problems such that in a close vs
         * open->hangup case this can be called after the final close so prevent
         * that from happening for now.
         */
-       if (hp->count <= 0) {
-               spin_unlock_irqrestore(&hp->lock, flags);
+       if (hp->port.count <= 0) {
+               spin_unlock_irqrestore(&hp->port.lock, flags);
                return;
        }
 
-       temp_open_count = hp->count;
-       hp->count = 0;
-       hp->n_outbuf = 0;
-       spin_unlock_irqrestore(&hp->lock, flags);
+       temp_open_count = hp->port.count;
+       hp->port.count = 0;
+       spin_unlock_irqrestore(&hp->port.lock, flags);
        tty_port_tty_set(&hp->port, NULL);
 
+       hp->n_outbuf = 0;
+
        if (hp->ops->notifier_hangup)
                hp->ops->notifier_hangup(hp, hp->data);
 
@@ -474,7 +475,8 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count
        if (!hp)
                return -EPIPE;
 
-       if (hp->count <= 0)
+       /* FIXME what's this (unprotected) check for? */
+       if (hp->port.count <= 0)
                return -EIO;
 
        spin_lock_irqsave(&hp->lock, flags);

diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h
index 594a28fe0da0bb5155e1de30b486d8d4b137ad99..674d23cb919afaeac34d5bc0c7bc8bbbd38c9c1f 100644 (file)
--- a/drivers/tty/hvc/hvc_console.h
+++ b/drivers/tty/hvc/hvc_console.h
@@ -49,7 +49,6 @@ struct hvc_struct {
        struct tty_port port;
        spinlock_t lock;
        int index;
-       int count;
        int do_wakeup;
        char *outbuf;
        int outbuf_size;