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yaml
---
r: 125078
b: refs/heads/master
c: fba85e0
h: refs/heads/master
v: v3
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Alan Cox authored and Linus Torvalds committed Jan 2, 2009
1 parent 66444ef commit c11921c
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Showing 3 changed files with 22 additions and 160 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 47b01b3a5fc7239f3e8d5d5cadc88afbea24d0c3
refs/heads/master: fba85e013f106a44e91ef5edec899fc56a7e61ee
177 changes: 18 additions & 159 deletions trunk/drivers/char/rocket.c
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Original file line number Diff line number Diff line change
Expand Up @@ -879,133 +879,33 @@ 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.
*/
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);
}

/*
Expand All @@ -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
Expand All @@ -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)
Expand All @@ -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
Expand All @@ -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);
Expand All @@ -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;

Expand All @@ -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
Expand Down Expand Up @@ -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));
Expand All @@ -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);

Expand Down Expand Up @@ -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);
Expand Down
3 changes: 3 additions & 0 deletions trunk/drivers/char/tty_port.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down

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