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TTY: HVC, use count from tty_port

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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>
This commit is contained in:
Jiri Slaby 2012-04-02 13:54:23 +02:00 committed by Greg Kroah-Hartman
parent 85bbc003b2
commit 0146b69390
2 changed files with 21 additions and 20 deletions
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40
drivers/tty/hvc/hvc_console.c
View File

@ -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);

1
drivers/tty/hvc/hvc_console.h
View File

@ -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;