[PATCH 56/75] tty: Make epca use the port helpers

Alan Cox
2009-01-02T13:47:57Z

From: Alan Cox <alan@redhat.com>

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>
---

drivers/char/epca.c | 172 +++++++----------------------------------------
drivers/char/tty_port.c | 3 +
2 files changed, 26 insertions(+), 149 deletions(-)

diff --git a/drivers/char/epca.c b/drivers/char/epca.c
index 7a69705..71225d1 100644
--- a/drivers/char/epca.c
+++ b/drivers/char/epca.c
@@ -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)
@@ -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
@@ -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);
}
}

@@ -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;
@@ -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;
/*
@@ -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;
@@ -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);
@@ -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);
}
@@ -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);
@@ -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);
@@ -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);
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index b3175f5..b580fcf 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -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;
}