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USB: serial: fix assumption that throttle/unthrottle cannot sleep 

many serial subdrivers are clearly written as if throttle/unthrottle
cannot sleep. This leads to unneeded atomic submissions. This
patch converts affected drivers in a way to makes very clear that
throttle/unthrottle can sleep. Thus future misdesigns can be avoided
and efficiency and reliability improved.

This removes any such assumption using GFP_KERNEL and spin_lock_irq()

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2009-10-07 10:50:23 +02:00 committed by Greg Kroah-Hartman
parent b2a5cf1bdc
commit 6383251545
10 changed files with 37 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/usb/serial/aircable.c
View File

@ -554,13 +554,12 @@ static void aircable_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->rx_lock, flags);
spin_lock_irq(&priv->rx_lock);
priv->rx_flags |= THROTTLED;
spin_unlock_irqrestore(&priv->rx_lock, flags);
spin_unlock_irq(&priv->rx_lock);
}
/* Based on ftdi_sio.c unthrottle */
@ -569,14 +568,13 @@ static void aircable_unthrottle(struct tty_struct *tty)
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
int actually_throttled;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->rx_lock, flags);
spin_lock_irq(&priv->rx_lock);
actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
spin_unlock_irqrestore(&priv->rx_lock, flags);
spin_unlock_irq(&priv->rx_lock);
if (actually_throttled)
schedule_work(&priv->rx_work);

12
drivers/usb/serial/cypress_m8.c
View File

@ -1155,13 +1155,12 @@ static void cypress_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct cypress_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
priv->rx_flags = THROTTLED;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
}
@ -1170,14 +1169,13 @@ static void cypress_unthrottle(struct tty_struct *tty)
struct usb_serial_port *port = tty->driver_data;
struct cypress_private *priv = usb_get_serial_port_data(port);
int actually_throttled, result;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
priv->rx_flags = 0;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
if (!priv->comm_is_ok)
return;
@ -1185,7 +1183,7 @@ static void cypress_unthrottle(struct tty_struct *tty)
if (actually_throttled) {
port->interrupt_in_urb->dev = port->serial->dev;
result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (result) {
dev_err(&port->dev, "%s - failed submitting read urb, "
"error %d\n", __func__, result);

2
drivers/usb/serial/empeg.c
View File

@ -391,7 +391,7 @@ static void empeg_unthrottle(struct tty_struct *tty)
dbg("%s - port %d", __func__, port->number);
port->read_urb->dev = port->serial->dev;
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
result = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",

12
drivers/usb/serial/garmin_gps.c
View File

@ -1390,14 +1390,13 @@ static void garmin_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
/* set flag, data received will be put into a queue
for later processing */
spin_lock_irqsave(&garmin_data_p->lock, flags);
spin_lock_irq(&garmin_data_p->lock);
garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
spin_unlock_irq(&garmin_data_p->lock);
}
@ -1405,13 +1404,12 @@ static void garmin_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
unsigned long flags;
int status;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&garmin_data_p->lock, flags);
spin_lock_irq(&garmin_data_p->lock);
garmin_data_p->flags &= ~FLAGS_THROTTLED;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
spin_unlock_irq(&garmin_data_p->lock);
/* in native mode send queued data to tty, in
serial mode nothing needs to be done here */
@ -1419,7 +1417,7 @@ static void garmin_unthrottle(struct tty_struct *tty)
garmin_flush_queue(garmin_data_p);
if (0 != (garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE)) {
status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
status = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (status)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",

2
drivers/usb/serial/keyspan_pda.c
View File

@ -290,7 +290,7 @@ static void keyspan_pda_rx_unthrottle(struct tty_struct *tty)
/* just restart the receive interrupt URB */
dbg("keyspan_pda_rx_unthrottle port %d", port->number);
port->interrupt_in_urb->dev = port->serial->dev;
if (usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC))
if (usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL))
dbg(" usb_submit_urb(read urb) failed");
return;
}

2
drivers/usb/serial/kl5kusb105.c
View File

@ -951,7 +951,7 @@ static void klsi_105_unthrottle(struct tty_struct *tty)
dbg("%s - port %d", __func__, port->number);
port->read_urb->dev = port->serial->dev;
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
result = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",

14
drivers/usb/serial/mct_u232.c
View File

@ -777,20 +777,19 @@ static void mct_u232_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct mct_u232_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
unsigned int control_state;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
priv->rx_flags |= THROTTLED;
if (C_CRTSCTS(tty)) {
priv->control_state &= ~TIOCM_RTS;
control_state = priv->control_state;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
(void) mct_u232_set_modem_ctrl(port->serial, control_state);
} else {
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
}
}
@ -799,20 +798,19 @@ static void mct_u232_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct mct_u232_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
unsigned int control_state;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
priv->rx_flags &= ~THROTTLED;
priv->control_state |= TIOCM_RTS;
control_state = priv->control_state;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
(void) mct_u232_set_modem_ctrl(port->serial, control_state);
} else {
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
}
}

12
drivers/usb/serial/symbolserial.c
View File

@ -165,33 +165,31 @@ static void symbol_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
priv->throttled = true;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
}
static void symbol_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
int result;
bool was_throttled;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
priv->throttled = false;
was_throttled = priv->actually_throttled;
priv->actually_throttled = false;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
priv->int_urb->dev = port->serial->dev;
if (was_throttled) {
result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",

12
drivers/usb/serial/visor.c
View File

@ -583,12 +583,11 @@ static void visor_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct visor_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
priv->throttled = 1;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
}
@ -596,17 +595,16 @@ static void visor_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct visor_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
int result;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
priv->throttled = 0;
priv->actually_throttled = 0;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
port->read_urb->dev = port->serial->dev;
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
result = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",

10
drivers/usb/serial/whiteheat.c
View File

@ -949,13 +949,12 @@ static void whiteheat_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&info->lock, flags);
spin_lock_irq(&info->lock);
info->flags |= THROTTLED;
spin_unlock_irqrestore(&info->lock, flags);
spin_unlock_irq(&info->lock);
return;
}
@ -966,14 +965,13 @@ static void whiteheat_unthrottle(struct tty_struct *tty)
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
int actually_throttled;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&info->lock, flags);
spin_lock_irq(&info->lock);
actually_throttled = info->flags & ACTUALLY_THROTTLED;
info->flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
spin_unlock_irqrestore(&info->lock, flags);
spin_unlock_irq(&info->lock);
if (actually_throttled)
rx_data_softint(&info->rx_work);