[PATCH 60/75] tty: use port methods for the rocket driver

Alan Cox
2009-01-02T13:48:25Z

From: Alan Cox <alan@redhat.com>

Now we have our ducks in order we can begin switching to the port
operations

Signed-off-by: Alan Cox <alan@redhat.com>
---

drivers/char/rocket.c | 177 +++++------------------------------------------
drivers/char/tty_port.c | 3 +
2 files changed, 21 insertions(+), 159 deletions(-)

diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index b5e5e77..f59fc5c 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -879,108 +879,6 @@ static void raise_dtr_rts(struct tty_port *port)
sSetRTS(&info->channel);
}

-/* info->port.count is considered critical, protected by spinlocks. */
-static int block_til_ready(struct tty_struct *tty, struct file *filp,
- struct r_port *info)
-{
- DECLARE_WAITQUEUE(wait, current);
- struct tty_port *port = &info->port;
- int retval;
- int do_clocal = 0, extra_count = 0;
- unsigned long flags;
-
- /*
- * If the device is in the middle of being closed, then block
- * until it's done, and then try again.
- */
- if (tty_hung_up_p(filp))
- return ((info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN : -ERESTARTSYS);
- if (info->flags & ASYNC_CLOSING) {
- if (wait_for_completion_interruptible(&info->close_wait))
- return -ERESTARTSYS;
- return ((info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN : -ERESTARTSYS);
- }
-
- /*
- * If non-blocking mode is set, or the port is not enabled,
- * then make the check up front and then exit.
- */
- if ((filp->f_flags & O_NONBLOCK) || (tty->flags & (1 << TTY_IO_ERROR))) {
- info->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. While we are in
- * this loop, port->count is dropped by one, so that rp_close() knows when to free things.
- * We restore it upon exit, either normal or abnormal.
- */
- retval = 0;
- add_wait_queue(&port->open_wait, &wait);
-#ifdef ROCKET_DEBUG_OPEN
- printk(KERN_INFO "block_til_ready before block: ttyR%d, count = %d\n", info->line, port->count);
-#endif
- spin_lock_irqsave(&port->lock, flags);
-
-#ifdef ROCKET_DISABLE_SIMUSAGE
- info->port.flags |= ASYNC_NORMAL_ACTIVE;
-#else
- if (!tty_hung_up_p(filp)) {
- extra_count = 1;
- port->count--;
- }
-#endif
- port->blocked_open++;
-
- spin_unlock_irqrestore(&port->lock, flags);
-
- while (1) {
- if (tty->termios->c_cflag & CBAUD)
- tty_port_raise_dtr_rts(port);
- set_current_state(TASK_INTERRUPTIBLE);
- if (tty_hung_up_p(filp) || !(info->port.flags & ASYNC_INITIALIZED)) {
- if (info->port.flags & ASYNC_HUP_NOTIFY)
- retval = -EAGAIN;
- else
- retval = -ERESTARTSYS;
- break;
- }
- if (!(info->port.flags & ASYNC_CLOSING) &&
- (do_clocal || tty_port_carrier_raised(port)))
- break;
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
-#ifdef ROCKET_DEBUG_OPEN
- printk(KERN_INFO "block_til_ready blocking: ttyR%d, count = %d, flags=0x%0x\n",
- info->line, port->count, info->port.flags);
-#endif
- schedule(); /* Don't hold spinlock here, will hang PC */
- }
- __set_current_state(TASK_RUNNING);
- remove_wait_queue(&port->open_wait, &wait);
-
- spin_lock_irqsave(&port->lock, flags);
-
- if (extra_count)
- port->count++;
- port->blocked_open--;
-
- spin_unlock_irqrestore(&port->lock, flags);
-
-#ifdef ROCKET_DEBUG_OPEN
- printk(KERN_INFO "block_til_ready after blocking: ttyR%d, count = %d\n",
- info->line, port->count);
-#endif
- if (retval)
- return retval;
- info->port.flags |= ASYNC_NORMAL_ACTIVE;
- return 0;
-}
-
/*
* Exception handler that opens a serial port. Creates xmit_buf storage, fills in
* port's r_port struct. Initializes the port hardware.
@@ -988,24 +886,26 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
static int rp_open(struct tty_struct *tty, struct file *filp)
{
struct r_port *info;
+ struct tty_port *port;
int line = 0, retval;
CHANNEL_t *cp;
unsigned long page;

line = tty->index;
- if ((line < 0) || (line >= MAX_RP_PORTS) || ((info = rp_table[line]) == NULL))
+ if (line < 0 || line >= MAX_RP_PORTS || ((info = rp_table[line]) == NULL))
return -ENXIO;
-
+ port = &info->port;
+
page = __get_free_page(GFP_KERNEL);
if (!page)
return -ENOMEM;

- if (info->port.flags & ASYNC_CLOSING) {
+ if (port->flags & ASYNC_CLOSING) {
retval = wait_for_completion_interruptible(&info->close_wait);
free_page(page);
if (retval)
return retval;
- return ((info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN : -ERESTARTSYS);
+ return ((port->flags & ASYNC_HUP_NOTIFY) ? -EAGAIN : -ERESTARTSYS);
}

/*
@@ -1017,9 +917,9 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
info->xmit_buf = (unsigned char *) page;

tty->driver_data = info;
- tty_port_tty_set(&info->port, tty);
+ tty_port_tty_set(port, tty);

- if (info->port.count++ == 0) {
+ if (port->count++ == 0) {
atomic_inc(&rp_num_ports_open);

#ifdef ROCKET_DEBUG_OPEN
@@ -1034,7 +934,7 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
/*
* Info->count is now 1; so it's safe to sleep now.
*/
- if ((info->port.flags & ASYNC_INITIALIZED) == 0) {
+ if (!test_bit(ASYNC_INITIALIZED, &port->flags)) {
cp = &info->channel;
sSetRxTrigger(cp, TRIG_1);
if (sGetChanStatus(cp) & CD_ACT)
@@ -1058,7 +958,7 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
sEnRxFIFO(cp);
sEnTransmit(cp);

- info->port.flags |= ASYNC_INITIALIZED;
+ set_bit(ASYNC_INITIALIZED, &info->port.flags);

/*
* Set up the tty->alt_speed kludge
@@ -1081,7 +981,7 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
/* Starts (or resets) the maint polling loop */
mod_timer(&rocket_timer, jiffies + POLL_PERIOD);

- retval = block_til_ready(tty, filp, info);
+ retval = tty_port_block_til_ready(port, tty, filp);
if (retval) {
#ifdef ROCKET_DEBUG_OPEN
printk(KERN_INFO "rp_open returning after block_til_ready with %d\n", retval);
@@ -1098,7 +998,6 @@ static void rp_close(struct tty_struct *tty, struct file *filp)
{
struct r_port *info = tty->driver_data;
struct tty_port *port = &info->port;
- unsigned long flags;
int timeout;
CHANNEL_t *cp;

@@ -1109,53 +1008,10 @@ static void rp_close(struct tty_struct *tty, struct file *filp)
printk(KERN_INFO "rp_close ttyR%d, count = %d\n", info->line, info->port.count);
#endif

- if (tty_hung_up_p(filp))
+ if (tty_port_close_start(port, tty, filp) == 0)
return;
- spin_lock_irqsave(&port->lock, flags);
-
- if (tty->count == 1 && port->count != 1) {
- /*
- * Uh, oh. tty->count is 1, which means that the tty
- * structure will be freed. Info->count should always
- * be one in these conditions. If it's greater than
- * one, we've got real problems, since it means the
- * serial port won't be shutdown.
- */
- printk(KERN_WARNING "rp_close: bad serial port count; "
- "tty->count is 1, info->port.count is %d\n", info->port.count);
- port->count = 1;
- }
- if (--port->count < 0) {
- printk(KERN_WARNING "rp_close: bad serial port count for "
- "ttyR%d: %d\n", info->line, info->port.count);
- port->count = 0;
- }
- if (port->count) {
- spin_unlock_irqrestore(&port->lock, flags);
- return;
- }
- info->port.flags |= ASYNC_CLOSING;
- spin_unlock_irqrestore(&port->lock, flags);

cp = &info->channel;
-
- /*
- * Notify the line discpline to only process XON/XOFF characters
- */
- tty->closing = 1;
-
- /*
- * If transmission was throttled by the application request,
- * just flush the xmit buffer.
- */
- if (tty->flow_stopped)
- rp_flush_buffer(tty);
-
- /*
- * Wait for the transmit buffer to clear
- */
- if (info->port.closing_wait != ASYNC_CLOSING_WAIT_NONE)
- tty_wait_until_sent(tty, port->closing_wait);
/*
* Before we drop DTR, make sure the UART transmitter
* has completely drained; this is especially
@@ -1184,6 +1040,9 @@ static void rp_close(struct tty_struct *tty, struct file *filp)

clear_bit((info->aiop * 8) + info->chan, (void *) &xmit_flags[info->board]);

+ /* We can't yet use tty_port_close_end as the buffer handling in this
+ driver is a bit different to the usual */
+
if (port->blocked_open) {
if (port->close_delay) {
msleep_interruptible(jiffies_to_msecs(port->close_delay));
@@ -1197,6 +1056,8 @@ static void rp_close(struct tty_struct *tty, struct file *filp)
}
info->port.flags &= ~(ASYNC_INITIALIZED | ASYNC_CLOSING | ASYNC_NORMAL_ACTIVE);
tty->closing = 0;
+ tty_port_tty_set(port, NULL);
+ wake_up_interruptible(&port->close_wait);
complete_all(&info->close_wait);
atomic_dec(&rp_num_ports_open);

@@ -1659,9 +1520,7 @@ static void rp_hangup(struct tty_struct *tty)
atomic_dec(&rp_num_ports_open);
clear_bit((info->aiop * 8) + info->chan, (void *) &xmit_flags[info->board]);

- info->port.count = 0;
- info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
- tty_port_tty_set(&info->port, NULL);
+ tty_port_hangup(&info->port);

cp = &info->channel;
sDisRxFIFO(cp);
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index b580fcf..9b8004c 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -286,6 +286,9 @@ 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);
+ /* Don't block on a stalled port, just pull the chain */
+ if (tty->flow_stopped)
+ tty_driver_flush_buffer(tty);
if (port->flags & ASYNC_INITIALIZED &&
port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, port->closing_wait);