tty: relock epca
Bring epca into line with the port locking. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox
Linus Torvalds
parent
542f548236
commit
d1c815e549
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@ -69,7 +69,9 @@ static int invalid_lilo_config;
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/*
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* The ISA boards do window flipping into the same spaces so its only sane with
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* a single lock. It's still pretty efficient.
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* a single lock. It's still pretty efficient. This lock guards the hardware
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* and the tty_port lock guards the kernel side stuff like use counts. Take
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* this lock inside the port lock if you must take both.
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*/
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static DEFINE_SPINLOCK(epca_lock);
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@ -156,7 +158,7 @@ static struct channel *verifyChannel(struct tty_struct *);
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static void pc_sched_event(struct channel *, int);
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static void epca_error(int, char *);
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static void pc_close(struct tty_struct *, struct file *);
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static void shutdown(struct channel *);
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static void shutdown(struct channel *, struct tty_struct *tty);
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static void pc_hangup(struct tty_struct *);
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static int pc_write_room(struct tty_struct *);
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static int pc_chars_in_buffer(struct tty_struct *);
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@ -419,76 +421,78 @@ static void epca_error(int line, char *msg)
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static void pc_close(struct tty_struct *tty, struct file *filp)
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{
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struct channel *ch;
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struct tty_port *port;
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unsigned long flags;
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/*
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* verifyChannel returns the channel from the tty struct if it is
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* valid. This serves as a sanity check.
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*/
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ch = verifyChannel(tty);
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if (ch != NULL) {
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spin_lock_irqsave(&epca_lock, flags);
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if (tty_hung_up_p(filp)) {
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spin_unlock_irqrestore(&epca_lock, flags);
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return;
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}
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if (ch->port.count-- > 1) {
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/* Begin channel is open more than once */
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/*
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* Return without doing anything. Someone might still
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* be using the channel.
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*/
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spin_unlock_irqrestore(&epca_lock, flags);
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return;
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}
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/* Port open only once go ahead with shutdown & reset */
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BUG_ON(ch->port.count < 0);
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if (ch == NULL)
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return;
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port = &ch->port;
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/*
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* Let the rest of the driver know the channel is being closed.
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* This becomes important if an open is attempted before close
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* is finished.
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*/
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ch->port.flags |= ASYNC_CLOSING;
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tty->closing = 1;
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spin_unlock_irqrestore(&epca_lock, flags);
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if (ch->port.flags & ASYNC_INITIALIZED) {
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/* Setup an event to indicate when the
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transmit buffer empties */
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setup_empty_event(tty, ch);
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/* 30 seconds timeout */
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tty_wait_until_sent(tty, 3000);
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}
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pc_flush_buffer(tty);
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tty_ldisc_flush(tty);
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shutdown(ch);
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spin_lock_irqsave(&epca_lock, flags);
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tty->closing = 0;
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ch->event = 0;
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ch->port.tty = NULL;
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spin_unlock_irqrestore(&epca_lock, flags);
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if (ch->port.blocked_open) {
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if (ch->close_delay)
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msleep_interruptible(jiffies_to_msecs(ch->close_delay));
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wake_up_interruptible(&ch->port.open_wait);
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}
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ch->port.flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED |
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ASYNC_CLOSING);
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wake_up_interruptible(&ch->port.close_wait);
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spin_lock_irqsave(&port->lock, flags);
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if (tty_hung_up_p(filp)) {
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spin_unlock_irqrestore(&port->lock, flags);
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return;
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}
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if (port->count-- > 1) {
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/* Begin channel is open more than once */
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/*
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* Return without doing anything. Someone might still
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* be using the channel.
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*/
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spin_unlock_irqrestore(&port->lock, flags);
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return;
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}
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/* Port open only once go ahead with shutdown & reset */
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WARN_ON(port->count < 0);
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/*
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* Let the rest of the driver know the channel is being closed.
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* This becomes important if an open is attempted before close
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* is finished.
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*/
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port->flags |= ASYNC_CLOSING;
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tty->closing = 1;
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spin_unlock_irqrestore(&port->lock, flags);
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if (port->flags & ASYNC_INITIALIZED) {
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/* Setup an event to indicate when the
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transmit buffer empties */
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setup_empty_event(tty, ch);
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/* 30 seconds timeout */
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tty_wait_until_sent(tty, 3000);
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}
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pc_flush_buffer(tty);
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tty_ldisc_flush(tty);
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shutdown(ch, tty);
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spin_lock_irqsave(&port->lock, flags);
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tty->closing = 0;
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ch->event = 0;
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port->tty = NULL;
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spin_unlock_irqrestore(&port->lock, flags);
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if (port->blocked_open) {
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if (ch->close_delay)
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msleep_interruptible(jiffies_to_msecs(ch->close_delay));
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wake_up_interruptible(&port->open_wait);
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}
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port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED |
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ASYNC_CLOSING);
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wake_up_interruptible(&port->close_wait);
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}
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static void shutdown(struct channel *ch)
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static void shutdown(struct channel *ch, struct tty_struct *tty)
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{
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unsigned long flags;
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struct tty_struct *tty;
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struct board_chan __iomem *bc;
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struct tty_port *port = &ch->port;
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if (!(ch->port.flags & ASYNC_INITIALIZED))
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if (!(port->flags & ASYNC_INITIALIZED))
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return;
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spin_lock_irqsave(&epca_lock, flags);
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@ -503,7 +507,6 @@ static void shutdown(struct channel *ch)
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*/
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if (bc)
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writeb(0, &bc->idata);
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tty = ch->port.tty;
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/* If we're a modem control device and HUPCL is on, drop RTS & DTR. */
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if (tty->termios->c_cflag & HUPCL) {
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@ -517,13 +520,15 @@ static void shutdown(struct channel *ch)
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* will have to reinitialized. Set a flag to indicate this.
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*/
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/* Prevent future Digi programmed interrupts from coming active */
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ch->port.flags &= ~ASYNC_INITIALIZED;
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port->flags &= ~ASYNC_INITIALIZED;
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spin_unlock_irqrestore(&epca_lock, flags);
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}
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static void pc_hangup(struct tty_struct *tty)
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{
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struct channel *ch;
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struct tty_port *port;
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/*
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* verifyChannel returns the channel from the tty struct if it is
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* valid. This serves as a sanity check.
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@ -531,18 +536,19 @@ static void pc_hangup(struct tty_struct *tty)
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ch = verifyChannel(tty);
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if (ch != NULL) {
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unsigned long flags;
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port = &ch->port;
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pc_flush_buffer(tty);
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tty_ldisc_flush(tty);
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shutdown(ch);
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shutdown(ch, tty);
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spin_lock_irqsave(&epca_lock, flags);
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ch->port.tty = NULL;
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ch->event = 0;
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ch->port.count = 0;
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ch->port.flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED);
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spin_unlock_irqrestore(&epca_lock, flags);
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wake_up_interruptible(&ch->port.open_wait);
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spin_lock_irqsave(&port->lock, flags);
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port->tty = NULL;
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ch->event = 0; /* FIXME: review locking of ch->event */
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port->count = 0;
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port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED);
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spin_unlock_irqrestore(&port->lock, flags);
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wake_up_interruptible(&port->open_wait);
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}
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}
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@ -792,9 +798,10 @@ static int block_til_ready(struct tty_struct *tty,
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DECLARE_WAITQUEUE(wait, current);
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int retval, do_clocal = 0;
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unsigned long flags;
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struct tty_port *port = &ch->port;
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if (tty_hung_up_p(filp)) {
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if (ch->port.flags & ASYNC_HUP_NOTIFY)
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if (port->flags & ASYNC_HUP_NOTIFY)
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retval = -EAGAIN;
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else
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retval = -ERESTARTSYS;
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@ -805,10 +812,10 @@ static int block_til_ready(struct tty_struct *tty,
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* If the device is in the middle of being closed, then block until
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* it's done, and then try again.
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*/
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if (ch->port.flags & ASYNC_CLOSING) {
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interruptible_sleep_on(&ch->port.close_wait);
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if (port->flags & ASYNC_CLOSING) {
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interruptible_sleep_on(&port->close_wait);
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if (ch->port.flags & ASYNC_HUP_NOTIFY)
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if (port->flags & ASYNC_HUP_NOTIFY)
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return -EAGAIN;
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else
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return -ERESTARTSYS;
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@ -819,7 +826,7 @@ static int block_til_ready(struct tty_struct *tty,
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* If non-blocking mode is set, then make the check up front
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* and then exit.
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*/
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ch->port.flags |= ASYNC_NORMAL_ACTIVE;
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port->flags |= ASYNC_NORMAL_ACTIVE;
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return 0;
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}
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if (tty->termios->c_cflag & CLOCAL)
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@ -827,31 +834,31 @@ static int block_til_ready(struct tty_struct *tty,
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/* Block waiting for the carrier detect and the line to become free */
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retval = 0;
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add_wait_queue(&ch->port.open_wait, &wait);
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add_wait_queue(&port->open_wait, &wait);
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spin_lock_irqsave(&epca_lock, flags);
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spin_lock_irqsave(&port->lock, flags);
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/* We dec count so that pc_close will know when to free things */
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if (!tty_hung_up_p(filp))
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ch->port.count--;
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ch->port.blocked_open++;
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port->count--;
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port->blocked_open++;
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while (1) {
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set_current_state(TASK_INTERRUPTIBLE);
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if (tty_hung_up_p(filp) ||
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!(ch->port.flags & ASYNC_INITIALIZED)) {
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if (ch->port.flags & ASYNC_HUP_NOTIFY)
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!(port->flags & ASYNC_INITIALIZED)) {
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if (port->flags & ASYNC_HUP_NOTIFY)
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retval = -EAGAIN;
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else
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retval = -ERESTARTSYS;
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break;
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}
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if (!(ch->port.flags & ASYNC_CLOSING) &&
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if (!(port->flags & ASYNC_CLOSING) &&
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(do_clocal || (ch->imodem & ch->dcd)))
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break;
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if (signal_pending(current)) {
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retval = -ERESTARTSYS;
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break;
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}
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spin_unlock_irqrestore(&epca_lock, flags);
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spin_unlock_irqrestore(&port->lock, flags);
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/*
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* Allow someone else to be scheduled. We will occasionally go
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* through this loop until one of the above conditions change.
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@ -859,27 +866,28 @@ static int block_til_ready(struct tty_struct *tty,
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* and prevent this loop from hogging the cpu.
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*/
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schedule();
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spin_lock_irqsave(&epca_lock, flags);
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spin_lock_irqsave(&port->lock, flags);
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}
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__set_current_state(TASK_RUNNING);
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remove_wait_queue(&ch->port.open_wait, &wait);
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remove_wait_queue(&port->open_wait, &wait);
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if (!tty_hung_up_p(filp))
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ch->port.count++;
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ch->port.blocked_open--;
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port->count++;
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port->blocked_open--;
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spin_unlock_irqrestore(&epca_lock, flags);
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spin_unlock_irqrestore(&port->lock, flags);
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if (retval)
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return retval;
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ch->port.flags |= ASYNC_NORMAL_ACTIVE;
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port->flags |= ASYNC_NORMAL_ACTIVE;
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return 0;
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}
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static int pc_open(struct tty_struct *tty, struct file *filp)
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{
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struct channel *ch;
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struct tty_port *port;
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unsigned long flags;
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int line, retval, boardnum;
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struct board_chan __iomem *bc;
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@ -890,6 +898,7 @@ static int pc_open(struct tty_struct *tty, struct file *filp)
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return -ENODEV;
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ch = &digi_channels[line];
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port = &ch->port;
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boardnum = ch->boardnum;
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/* Check status of board configured in system. */
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@ -926,22 +935,24 @@ static int pc_open(struct tty_struct *tty, struct file *filp)
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return -ENODEV;
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}
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spin_lock_irqsave(&epca_lock, flags);
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spin_lock_irqsave(&port->lock, flags);
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/*
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* Every time a channel is opened, increment a counter. This is
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* necessary because we do not wish to flush and shutdown the channel
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* until the last app holding the channel open, closes it.
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*/
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ch->port.count++;
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port->count++;
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/*
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* Set a kernel structures pointer to our local channel structure. This
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* way we can get to it when passed only a tty struct.
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*/
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tty->driver_data = ch;
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port->tty = tty;
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/*
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* If this is the first time the channel has been opened, initialize
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* the tty->termios struct otherwise let pc_close handle it.
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*/
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spin_lock(&epca_lock);
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globalwinon(ch);
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ch->statusflags = 0;
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@ -956,16 +967,16 @@ static int pc_open(struct tty_struct *tty, struct file *filp)
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writew(head, &bc->rout);
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/* Set the channels associated tty structure */
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ch->port.tty = tty;
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/*
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* The below routine generally sets up parity, baud, flow control
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* issues, etc.... It effect both control flags and input flags.
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*/
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epcaparam(tty, ch);
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ch->port.flags |= ASYNC_INITIALIZED;
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memoff(ch);
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spin_unlock_irqrestore(&epca_lock, flags);
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spin_unlock(&epca_lock);
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port->flags |= ASYNC_INITIALIZED;
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spin_unlock_irqrestore(&port->lock, flags);
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retval = block_til_ready(tty, filp, ch);
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if (retval)
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@ -974,13 +985,15 @@ static int pc_open(struct tty_struct *tty, struct file *filp)
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* Set this again in case a hangup set it to zero while this open() was
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* waiting for the line...
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*/
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spin_lock_irqsave(&epca_lock, flags);
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ch->port.tty = tty;
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spin_lock_irqsave(&port->lock, flags);
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port->tty = tty;
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spin_lock(&epca_lock);
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globalwinon(ch);
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/* Enable Digi Data events */
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writeb(1, &bc->idata);
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memoff(ch);
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spin_unlock_irqrestore(&epca_lock, flags);
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spin_unlock(&epca_lock);
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spin_unlock_irqrestore(&port->lock, flags);
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return 0;
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}
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