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>
diff --git a/drivers/usb/serial/aircable.c b/drivers/usb/serial/aircable.c
index 2cbfab3..b10ac84 100644
--- a/drivers/usb/serial/aircable.c
+++ b/drivers/usb/serial/aircable.c
@@ -554,13 +554,12 @@
{
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 @@
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);
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index e0a8b71..a591ebe 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -1155,13 +1155,12 @@
{
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 @@
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 @@
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);
diff --git a/drivers/usb/serial/empeg.c b/drivers/usb/serial/empeg.c
index 33c9e9c..7dd0e3e 100644
--- a/drivers/usb/serial/empeg.c
+++ b/drivers/usb/serial/empeg.c
@@ -391,7 +391,7 @@
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",
diff --git a/drivers/usb/serial/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index 20432d3..5ac900e 100644
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -1390,14 +1390,13 @@
{
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 @@
{
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 @@
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",
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 257c16c..1296a09 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -290,7 +290,7 @@
/* 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;
}
diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index f737337..3a78738 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -951,7 +951,7 @@
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",
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index ad4998b..cd009cb 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -777,20 +777,19 @@
{
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 @@
{
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);
}
}
diff --git a/drivers/usb/serial/symbolserial.c b/drivers/usb/serial/symbolserial.c
index f25e545..b282c0f 100644
--- a/drivers/usb/serial/symbolserial.c
+++ b/drivers/usb/serial/symbolserial.c
@@ -165,33 +165,31 @@
{
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",
diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
index 8e2d6dd..b9341f0 100644
--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c
@@ -583,12 +583,11 @@
{
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 @@
{
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",
diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 62424ee..1093d2e 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -949,13 +949,12 @@
{
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 @@
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);