* [PATCH 1/4] serial: Change the wait for carrier locking
2010-05-19 12:13 [PATCH 0/4] serial: move towards tty_port Alan Cox
@ 2010-05-19 12:13 ` Alan Cox
2010-05-19 12:14 ` [PATCH 2/4] serial: add port helpers Alan Cox
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Alan Cox @ 2010-05-19 12:13 UTC (permalink / raw)
To: greg, linux-serial
We want to push the lock/unlock into the helper functions so that we
can prepare to move to using the tty_port helper. The expansion initially
comes out a bit ugly but its worth the temporary expansion IMHO just so
we can produce a nice testable series of changes.
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/serial/serial_core.c | 44 +++++++++++++++++++++++++++++++++---------
1 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 570dca2..424b1c7 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1272,6 +1272,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
struct uart_state *state = tty->driver_data;
struct tty_port *port;
struct uart_port *uport;
+ unsigned long flags;
BUG_ON(!kernel_locked());
@@ -1284,9 +1285,12 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
pr_debug("uart_close(%d) called\n", uport->line);
mutex_lock(&port->mutex);
+ spin_lock_irqsave(&port->lock, flags);
- if (tty_hung_up_p(filp))
+ if (tty_hung_up_p(filp)) {
+ spin_unlock_irqrestore(&port->lock, flags);
goto done;
+ }
if ((tty->count == 1) && (port->count != 1)) {
/*
@@ -1305,8 +1309,10 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
tty->name, port->count);
port->count = 0;
}
- if (port->count)
+ if (port->count) {
+ spin_unlock_irqrestore(&port->lock, flags);
goto done;
+ }
/*
* Now we wait for the transmit buffer to clear; and we notify
@@ -1314,6 +1320,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
* setting tty->closing.
*/
tty->closing = 1;
+ spin_unlock_irqrestore(&port->lock, flags);
if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, msecs_to_jiffies(port->closing_wait));
@@ -1340,20 +1347,26 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
tty_ldisc_flush(tty);
- tty->closing = 0;
tty_port_tty_set(port, NULL);
+ spin_lock_irqsave(&port->lock, flags);
+ tty->closing = 0;
if (port->blocked_open) {
+ spin_unlock_irqrestore(&port->lock, flags);
if (port->close_delay)
msleep_interruptible(port->close_delay);
+ spin_lock_irqsave(&port->lock, flags);
} else if (!uart_console(uport)) {
+ spin_unlock_irqrestore(&port->lock, flags);
uart_change_pm(state, 3);
+ spin_lock_irqsave(&port->lock, flags);
}
/*
* Wake up anyone trying to open this port.
*/
clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
done:
@@ -1429,6 +1442,7 @@ static void uart_hangup(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
struct tty_port *port = &state->port;
+ unsigned long flags;
BUG_ON(!kernel_locked());
pr_debug("uart_hangup(%d)\n", state->uart_port->line);
@@ -1437,8 +1451,10 @@ static void uart_hangup(struct tty_struct *tty)
if (port->flags & ASYNC_NORMAL_ACTIVE) {
uart_flush_buffer(tty);
uart_shutdown(tty, state);
+ spin_lock_irqsave(&port->lock, flags);
port->count = 0;
clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
tty_port_tty_set(port, NULL);
wake_up_interruptible(&port->open_wait);
wake_up_interruptible(&port->delta_msr_wait);
@@ -1496,9 +1512,13 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
struct uart_port *uport = state->uart_port;
struct tty_port *port = &state->port;
unsigned int mctrl;
+ unsigned long flags;
+ spin_lock_irqsave(&port->lock, flags);
+ if (!tty_hung_up_p(filp))
+ port->count--;
port->blocked_open++;
- port->count--;
+ spin_unlock_irqrestore(&port->lock, flags);
add_wait_queue(&port->open_wait, &wait);
while (1) {
@@ -1535,23 +1555,26 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
* not set RTS here - we want to make sure we catch
* the data from the modem.
*/
- if (port->tty->termios->c_cflag & CBAUD)
+ if (port->tty->termios->c_cflag & CBAUD) {
+ mutex_lock(&port->mutex);
uart_set_mctrl(uport, TIOCM_DTR);
+ mutex_unlock(&port->mutex);
+ }
/*
* and wait for the carrier to indicate that the
* modem is ready for us.
*/
+ mutex_lock(&port->mutex);
spin_lock_irq(&uport->lock);
uport->ops->enable_ms(uport);
mctrl = uport->ops->get_mctrl(uport);
spin_unlock_irq(&uport->lock);
+ mutex_unlock(&port->mutex);
if (mctrl & TIOCM_CAR)
break;
- mutex_unlock(&port->mutex);
schedule();
- mutex_lock(&port->mutex);
if (signal_pending(current))
break;
@@ -1559,8 +1582,11 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
set_current_state(TASK_RUNNING);
remove_wait_queue(&port->open_wait, &wait);
- port->count++;
+ spin_lock_irqsave(&port->lock, flags);
+ if (!tty_hung_up_p(filp))
+ port->count++;
port->blocked_open--;
+ spin_unlock_irqrestore(&port->lock, flags);
if (signal_pending(current))
return -ERESTARTSYS;
@@ -1677,9 +1703,9 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
/*
* If we succeeded, wait until the port is ready.
*/
+ mutex_unlock(&port->mutex);
if (retval == 0)
retval = uart_block_til_ready(filp, state);
- mutex_unlock(&port->mutex);
/*
* If this is the first open to succeed, adjust things to suit.
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/4] serial: add port helpers
2010-05-19 12:13 [PATCH 0/4] serial: move towards tty_port Alan Cox
2010-05-19 12:13 ` [PATCH 1/4] serial: Change the wait for carrier locking Alan Cox
@ 2010-05-19 12:14 ` Alan Cox
2010-05-19 12:14 ` [PATCH 3/4] serial: trim locking on the helpers Alan Cox
2010-05-19 12:14 ` [PATCH 4/4] serial: Use block_til_ready helper Alan Cox
3 siblings, 0 replies; 5+ messages in thread
From: Alan Cox @ 2010-05-19 12:14 UTC (permalink / raw)
To: greg, linux-serial
We can make this the same as the ones that will be needed by the tty_port
helper logic that we want to move to but still call them from the existing
code base.
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/serial/serial_core.c | 51 ++++++++++++++++++++++++++++++------------
1 files changed, 37 insertions(+), 14 deletions(-)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 424b1c7..2379045 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1501,6 +1501,34 @@ static void uart_update_termios(struct tty_struct *tty,
}
}
+static int uart_carrier_raised(struct tty_port *port)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
+ int mctrl;
+ mutex_lock(&port->mutex);
+ spin_lock_irq(&uport->lock);
+ uport->ops->enable_ms(uport);
+ mctrl = uport->ops->get_mctrl(uport);
+ spin_unlock_irq(&uport->lock);
+ mutex_unlock(&port->mutex);
+ if (mctrl & TIOCM_CAR)
+ return 1;
+ return 0;
+}
+
+static void uart_dtr_rts(struct tty_port *port, int onoff)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
+ mutex_lock(&port->mutex);
+ if (onoff)
+ uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+ else
+ uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+ mutex_unlock(&port->mutex);
+}
+
/*
* Block the open until the port is ready. We must be called with
* the per-port semaphore held.
@@ -1509,9 +1537,7 @@ static int
uart_block_til_ready(struct file *filp, struct uart_state *state)
{
DECLARE_WAITQUEUE(wait, current);
- struct uart_port *uport = state->uart_port;
struct tty_port *port = &state->port;
- unsigned int mctrl;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
@@ -1555,23 +1581,14 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
* not set RTS here - we want to make sure we catch
* the data from the modem.
*/
- if (port->tty->termios->c_cflag & CBAUD) {
- mutex_lock(&port->mutex);
- uart_set_mctrl(uport, TIOCM_DTR);
- mutex_unlock(&port->mutex);
- }
+ if (port->tty->termios->c_cflag & CBAUD)
+ tty_port_raise_dtr_rts(port);
/*
* and wait for the carrier to indicate that the
* modem is ready for us.
*/
- mutex_lock(&port->mutex);
- spin_lock_irq(&uport->lock);
- uport->ops->enable_ms(uport);
- mctrl = uport->ops->get_mctrl(uport);
- spin_unlock_irq(&uport->lock);
- mutex_unlock(&port->mutex);
- if (mctrl & TIOCM_CAR)
+ if (tty_port_carrier_raised(port))
break;
schedule();
@@ -2349,6 +2366,11 @@ static const struct tty_operations uart_ops = {
#endif
};
+static const struct tty_port_operations uart_port_ops = {
+ .carrier_raised = uart_carrier_raised,
+ .dtr_rts = uart_dtr_rts,
+};
+
/**
* uart_register_driver - register a driver with the uart core layer
* @drv: low level driver structure
@@ -2405,6 +2427,7 @@ int uart_register_driver(struct uart_driver *drv)
struct tty_port *port = &state->port;
tty_port_init(port);
+ port->ops = &uart_port_ops;
port->close_delay = 500; /* .5 seconds */
port->closing_wait = 30000; /* 30 seconds */
tasklet_init(&state->tlet, uart_tasklet_action,
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/4] serial: trim locking on the helpers
2010-05-19 12:13 [PATCH 0/4] serial: move towards tty_port Alan Cox
2010-05-19 12:13 ` [PATCH 1/4] serial: Change the wait for carrier locking Alan Cox
2010-05-19 12:14 ` [PATCH 2/4] serial: add port helpers Alan Cox
@ 2010-05-19 12:14 ` Alan Cox
2010-05-19 12:14 ` [PATCH 4/4] serial: Use block_til_ready helper Alan Cox
3 siblings, 0 replies; 5+ messages in thread
From: Alan Cox @ 2010-05-19 12:14 UTC (permalink / raw)
To: greg, linux-serial
The port mutex protects port->tty, but these paths never need to walk from
port->tty. They do need the low level lock as the API expects that but they
already also take it.
Thus we can drop the extra mutex lock calls here.
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/serial/serial_core.c | 5 +----
1 files changed, 1 insertions(+), 4 deletions(-)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 2379045..0603e0d 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1506,12 +1506,10 @@ static int uart_carrier_raised(struct tty_port *port)
struct uart_state *state = container_of(port, struct uart_state, port);
struct uart_port *uport = state->uart_port;
int mctrl;
- mutex_lock(&port->mutex);
spin_lock_irq(&uport->lock);
uport->ops->enable_ms(uport);
mctrl = uport->ops->get_mctrl(uport);
spin_unlock_irq(&uport->lock);
- mutex_unlock(&port->mutex);
if (mctrl & TIOCM_CAR)
return 1;
return 0;
@@ -1521,12 +1519,11 @@ static void uart_dtr_rts(struct tty_port *port, int onoff)
{
struct uart_state *state = container_of(port, struct uart_state, port);
struct uart_port *uport = state->uart_port;
- mutex_lock(&port->mutex);
+
if (onoff)
uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
else
uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
- mutex_unlock(&port->mutex);
}
/*
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 4/4] serial: Use block_til_ready helper
2010-05-19 12:13 [PATCH 0/4] serial: move towards tty_port Alan Cox
` (2 preceding siblings ...)
2010-05-19 12:14 ` [PATCH 3/4] serial: trim locking on the helpers Alan Cox
@ 2010-05-19 12:14 ` Alan Cox
3 siblings, 0 replies; 5+ messages in thread
From: Alan Cox @ 2010-05-19 12:14 UTC (permalink / raw)
To: greg, linux-serial
Our code now rather closely resembles the helper, so switch to it.
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/serial/serial_core.c | 87 ------------------------------------------
1 files changed, 1 insertions(+), 86 deletions(-)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0603e0d..a55751a 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1526,91 +1526,6 @@ static void uart_dtr_rts(struct tty_port *port, int onoff)
uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
}
-/*
- * Block the open until the port is ready. We must be called with
- * the per-port semaphore held.
- */
-static int
-uart_block_til_ready(struct file *filp, struct uart_state *state)
-{
- DECLARE_WAITQUEUE(wait, current);
- struct tty_port *port = &state->port;
- unsigned long flags;
-
- spin_lock_irqsave(&port->lock, flags);
- if (!tty_hung_up_p(filp))
- port->count--;
- port->blocked_open++;
- spin_unlock_irqrestore(&port->lock, flags);
-
- add_wait_queue(&port->open_wait, &wait);
- while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
-
- /*
- * If we have been hung up, tell userspace/restart open.
- */
- if (tty_hung_up_p(filp) || port->tty == NULL)
- break;
-
- /*
- * If the port has been closed, tell userspace/restart open.
- */
- if (!(port->flags & ASYNC_INITIALIZED))
- break;
-
- /*
- * If non-blocking mode is set, or CLOCAL mode is set,
- * we don't want to wait for the modem status lines to
- * indicate that the port is ready.
- *
- * Also, if the port is not enabled/configured, we want
- * to allow the open to succeed here. Note that we will
- * have set TTY_IO_ERROR for a non-existant port.
- */
- if ((filp->f_flags & O_NONBLOCK) ||
- (port->tty->termios->c_cflag & CLOCAL) ||
- (port->tty->flags & (1 << TTY_IO_ERROR)))
- break;
-
- /*
- * Set DTR to allow modem to know we're waiting. Do
- * not set RTS here - we want to make sure we catch
- * the data from the modem.
- */
- if (port->tty->termios->c_cflag & CBAUD)
- tty_port_raise_dtr_rts(port);
-
- /*
- * and wait for the carrier to indicate that the
- * modem is ready for us.
- */
- if (tty_port_carrier_raised(port))
- break;
-
- schedule();
-
- if (signal_pending(current))
- break;
- }
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&port->open_wait, &wait);
-
- spin_lock_irqsave(&port->lock, flags);
- if (!tty_hung_up_p(filp))
- port->count++;
- port->blocked_open--;
- spin_unlock_irqrestore(&port->lock, flags);
-
- if (signal_pending(current))
- return -ERESTARTSYS;
-
- if (!port->tty || tty_hung_up_p(filp))
- return -EAGAIN;
-
- return 0;
-}
-
static struct uart_state *uart_get(struct uart_driver *drv, int line)
{
struct uart_state *state;
@@ -1719,7 +1634,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
*/
mutex_unlock(&port->mutex);
if (retval == 0)
- retval = uart_block_til_ready(filp, state);
+ retval = tty_port_block_til_ready(port, tty, filp);
/*
* If this is the first open to succeed, adjust things to suit.
^ permalink raw reply related [flat|nested] 5+ messages in thread