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tty: Make epca use the port helpers
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Now the locking is straight and the port kref usage is straight we can
replace lots of chunks of code with the standard port helpers

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alan Cox authored and Linus Torvalds committed Jan 2, 2009
1 parent 3969ffb commit 6ed1dba
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Showing 2 changed files with 26 additions and 149 deletions.
172 changes: 24 additions & 148 deletions drivers/char/epca.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -432,58 +432,15 @@ static void pc_close(struct tty_struct *tty, struct file *filp)
return;
port = &ch->port;

spin_lock_irqsave(&port->lock, flags);
if (tty_hung_up_p(filp)) {
spin_unlock_irqrestore(&port->lock, flags);
return;
}
if (port->count-- > 1) {
/* Begin channel is open more than once */
/*
* Return without doing anything. Someone might still
* be using the channel.
*/
spin_unlock_irqrestore(&port->lock, flags);
if (tty_port_close_start(port, tty, filp) == 0)
return;
}
/* Port open only once go ahead with shutdown & reset */
WARN_ON(port->count < 0);

/*
* Let the rest of the driver know the channel is being closed.
* This becomes important if an open is attempted before close
* is finished.
*/
port->flags |= ASYNC_CLOSING;
tty->closing = 1;

spin_unlock_irqrestore(&port->lock, flags);

if (port->flags & ASYNC_INITIALIZED) {
/* Setup an event to indicate when the
transmit buffer empties */
setup_empty_event(tty, ch);
/* 30 seconds timeout */
tty_wait_until_sent(tty, 3000);
}
pc_flush_buffer(tty);
tty_ldisc_flush(tty);
shutdown(ch, tty);

spin_lock_irqsave(&port->lock, flags);
tty->closing = 0;
ch->event = 0;
tty_port_close_end(port, tty);
ch->event = 0; /* FIXME: review ch->event locking */
tty_port_tty_set(port, NULL);
spin_unlock_irqrestore(&port->lock, flags);

if (port->blocked_open) {
if (ch->close_delay)
msleep_interruptible(jiffies_to_msecs(ch->close_delay));
wake_up_interruptible(&port->open_wait);
}
port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED |
ASYNC_CLOSING);
wake_up_interruptible(&port->close_wait);
}

static void shutdown(struct channel *ch, struct tty_struct *tty)
Expand Down Expand Up @@ -527,7 +484,6 @@ static void shutdown(struct channel *ch, struct tty_struct *tty)
static void pc_hangup(struct tty_struct *tty)
{
struct channel *ch;
struct tty_port *port;

/*
* verifyChannel returns the channel from the tty struct if it is
Expand All @@ -536,19 +492,13 @@ static void pc_hangup(struct tty_struct *tty)
ch = verifyChannel(tty);
if (ch != NULL) {
unsigned long flags;
port = &ch->port;

pc_flush_buffer(tty);
tty_ldisc_flush(tty);
shutdown(ch, tty);

spin_lock_irqsave(&port->lock, flags);
port->tty = NULL;
ch->event = 0; /* FIXME: review locking of ch->event */
port->count = 0;
port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED);
spin_unlock_irqrestore(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
tty_port_hangup(&ch->port);
}
}

Expand Down Expand Up @@ -792,98 +742,18 @@ static void pc_flush_chars(struct tty_struct *tty)
}
}

static int block_til_ready(struct tty_struct *tty,
struct file *filp, struct channel *ch)
static int epca_carrier_raised(struct tty_port *port)
{
DECLARE_WAITQUEUE(wait, current);
int retval, do_clocal = 0;
unsigned long flags;
struct tty_port *port = &ch->port;

if (tty_hung_up_p(filp)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
return retval;
}

/*
* If the device is in the middle of being closed, then block until
* it's done, and then try again.
*/
if (port->flags & ASYNC_CLOSING) {
interruptible_sleep_on(&port->close_wait);

if (port->flags & ASYNC_HUP_NOTIFY)
return -EAGAIN;
else
return -ERESTARTSYS;
}

if (filp->f_flags & O_NONBLOCK) {
/*
* If non-blocking mode is set, then make the check up front
* and then exit.
*/
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
if (tty->termios->c_cflag & CLOCAL)
do_clocal = 1;
/* Block waiting for the carrier detect and the line to become free */

retval = 0;
add_wait_queue(&port->open_wait, &wait);

spin_lock_irqsave(&port->lock, flags);
/* We dec count so that pc_close will know when to free things */
if (!tty_hung_up_p(filp))
port->count--;
port->blocked_open++;
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(port->flags & ASYNC_INITIALIZED)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
break;
}
if (!(port->flags & ASYNC_CLOSING) &&
(do_clocal || (ch->imodem & ch->dcd)))
break;
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
spin_unlock_irqrestore(&port->lock, flags);
/*
* Allow someone else to be scheduled. We will occasionally go
* through this loop until one of the above conditions change.
* The below schedule call will allow other processes to enter
* and prevent this loop from hogging the cpu.
*/
schedule();
spin_lock_irqsave(&port->lock, flags);
}

__set_current_state(TASK_RUNNING);
remove_wait_queue(&port->open_wait, &wait);
if (!tty_hung_up_p(filp))
port->count++;
port->blocked_open--;

spin_unlock_irqrestore(&port->lock, flags);

if (retval)
return retval;

port->flags |= ASYNC_NORMAL_ACTIVE;
struct channel *ch = container_of(port, struct channel, port);
if (ch->imodem & ch->dcd)
return 1;
return 0;
}

static void epca_raise_dtr_rts(struct tty_port *port0
{
}

static int pc_open(struct tty_struct *tty, struct file *filp)
{
struct channel *ch;
Expand Down Expand Up @@ -978,7 +848,7 @@ static int pc_open(struct tty_struct *tty, struct file *filp)
port->flags |= ASYNC_INITIALIZED;
spin_unlock_irqrestore(&port->lock, flags);

retval = block_til_ready(tty, filp, ch);
retval = tty_port_block_til_ready(port, tty, filp);
if (retval)
return retval;
/*
Expand Down Expand Up @@ -1058,6 +928,11 @@ static const struct tty_operations pc_ops = {
.break_ctl = pc_send_break
};

static const struct tty_port_operations epca_port_ops = {
.carrier_raised = epca_carrier_raised,
.raise_dtr_rts = epca_raise_dtr_rts,
};

static int info_open(struct tty_struct *tty, struct file *filp)
{
return 0;
Expand Down Expand Up @@ -1393,6 +1268,7 @@ static void post_fep_init(unsigned int crd)
u16 tseg, rseg;

tty_port_init(&ch->port);
ch->port.ops - &epca_port_ops;
ch->brdchan = bc;
ch->mailbox = gd;
INIT_WORK(&ch->tqueue, do_softint);
Expand Down Expand Up @@ -1526,7 +1402,7 @@ static void post_fep_init(unsigned int crd)
ch->fepstartca = 0;
ch->fepstopca = 0;

ch->close_delay = 50;
ch->port.close_delay = 50;

spin_unlock_irqrestore(&epca_lock, flags);
}
Expand Down Expand Up @@ -1647,7 +1523,7 @@ static void doevent(int crd)
if (event & MODEMCHG_IND) {
/* A modem signal change has been indicated */
ch->imodem = mstat;
if (ch->port.flags & ASYNC_CHECK_CD) {
if (test_bit(ASYNC_CHECK_CD, &ch->port.flags)) {
/* We are now receiving dcd */
if (mstat & ch->dcd)
wake_up_interruptible(&ch->port.open_wait);
Expand Down Expand Up @@ -1894,9 +1770,9 @@ static void epcaparam(struct tty_struct *tty, struct channel *ch)
* that the driver will wait on carrier detect.
*/
if (ts->c_cflag & CLOCAL)
ch->port.flags &= ~ASYNC_CHECK_CD;
clear_bit(ASYNC_CHECK_CD, &ch->port.flags);
else
ch->port.flags |= ASYNC_CHECK_CD;
set_bit(ASYNC_CHECK_CD, &ch->port.flags);
mval = ch->m_dtr | ch->m_rts;
} /* End CBAUD not detected */
iflag = termios2digi_i(ch, ts->c_iflag);
Expand Down Expand Up @@ -2373,7 +2249,7 @@ static void do_softint(struct work_struct *work)
if (test_and_clear_bit(EPCA_EVENT_HANGUP, &ch->event)) {
tty_hangup(tty);
wake_up_interruptible(&ch->port.open_wait);
ch->port.flags &= ~ASYNC_NORMAL_ACTIVE;
clear_bit(ASYNC_NORMAL_ACTIVE, &ch->port.flags);
}
}
tty_kref_put(tty);
Expand Down
3 changes: 2 additions & 1 deletion drivers/char/tty_port.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -286,7 +286,8 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
port->flags |= ASYNC_CLOSING;
tty->closing = 1;
spin_unlock_irqrestore(&port->lock, flags);
if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
if (port->flags & ASYNC_INITIALIZED &&
port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, port->closing_wait);
return 1;
}
Expand Down

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