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authorAlan Cox <alan@lxorguk.ukuu.org.uk>2008-04-08 17:16:06 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-24 21:16:55 -0700
commita5b6f60c5a30c494017c7a2d11c4067f90d3d0df (patch)
tree2f80d1a6c2655c5c12f40cafbc47516284934d42
parent441b62c1edb986827154768d89bbac0ba779984f (diff)
usb serial: more fixes and groundwork for tty changes
- If a termios change fails due to lack of memory we should copy the old settings back over as the device has not changed - Note various locking problems - kl5kusb105 had various remaining tty flag handling problems - Make safe_serial use tty_insert_flip_string not open coded loops - set termios speed properly in usb_serial Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/serial/ark3116.c1
-rw-r--r--drivers/usb/serial/cyberjack.c31
-rw-r--r--drivers/usb/serial/generic.c5
-rw-r--r--drivers/usb/serial/keyspan.c19
-rw-r--r--drivers/usb/serial/keyspan_pda.c9
-rw-r--r--drivers/usb/serial/kl5kusb105.c41
-rw-r--r--drivers/usb/serial/mos7720.c1
-rw-r--r--drivers/usb/serial/navman.c10
-rw-r--r--drivers/usb/serial/omninet.c3
-rw-r--r--drivers/usb/serial/option.c3
-rw-r--r--drivers/usb/serial/pl2303.c2
-rw-r--r--drivers/usb/serial/safe_serial.c27
-rw-r--r--drivers/usb/serial/sierra.c2
-rw-r--r--drivers/usb/serial/usb-serial.c2
-rw-r--r--drivers/usb/serial/visor.c2
-rw-r--r--drivers/usb/serial/whiteheat.c2
16 files changed, 93 insertions, 67 deletions
diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
index 9d708b22e95..599ab2e548a 100644
--- a/drivers/usb/serial/ark3116.c
+++ b/drivers/usb/serial/ark3116.c
@@ -192,6 +192,7 @@ static void ark3116_set_termios(struct usb_serial_port *port,
buf = kmalloc(1, GFP_KERNEL);
if (!buf) {
dbg("error kmalloc");
+ *port->tty->termios = *old_termios;
return;
}
diff --git a/drivers/usb/serial/cyberjack.c b/drivers/usb/serial/cyberjack.c
index 5348e97b52b..d077534ceae 100644
--- a/drivers/usb/serial/cyberjack.c
+++ b/drivers/usb/serial/cyberjack.c
@@ -151,7 +151,7 @@ static void cyberjack_shutdown (struct usb_serial *serial)
dbg("%s", __func__);
- for (i=0; i < serial->num_ports; ++i) {
+ for (i = 0; i < serial->num_ports; ++i) {
usb_kill_urb(serial->port[i]->interrupt_in_urb);
/* My special items, the standard routines free my urbs */
kfree(usb_get_serial_port_data(serial->port[i]));
@@ -209,7 +209,7 @@ static int cyberjack_write (struct usb_serial_port *port, const unsigned char *b
if (count == 0) {
dbg("%s - write request of 0 bytes", __func__);
- return (0);
+ return 0;
}
spin_lock_bh(&port->lock);
@@ -223,12 +223,12 @@ static int cyberjack_write (struct usb_serial_port *port, const unsigned char *b
spin_lock_irqsave(&priv->lock, flags);
- if( (count+priv->wrfilled)>sizeof(priv->wrbuf) ) {
+ if( (count+priv->wrfilled) > sizeof(priv->wrbuf) ) {
/* To much data for buffer. Reset buffer. */
- priv->wrfilled=0;
- spin_unlock_irqrestore(&priv->lock, flags);
+ priv->wrfilled = 0;
port->write_urb_busy = 0;
- return (0);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return 0;
}
/* Copy data */
@@ -269,8 +269,8 @@ static int cyberjack_write (struct usb_serial_port *port, const unsigned char *b
if (result) {
err("%s - failed submitting write urb, error %d", __func__, result);
/* Throw away data. No better idea what to do with it. */
- priv->wrfilled=0;
- priv->wrsent=0;
+ priv->wrfilled = 0;
+ priv->wrsent = 0;
spin_unlock_irqrestore(&priv->lock, flags);
port->write_urb_busy = 0;
return 0;
@@ -282,8 +282,8 @@ static int cyberjack_write (struct usb_serial_port *port, const unsigned char *b
if( priv->wrsent>=priv->wrfilled ) {
dbg("%s - buffer cleaned", __func__);
memset( priv->wrbuf, 0, sizeof(priv->wrbuf) );
- priv->wrfilled=0;
- priv->wrsent=0;
+ priv->wrfilled = 0;
+ priv->wrsent = 0;
}
}
@@ -294,6 +294,7 @@ static int cyberjack_write (struct usb_serial_port *port, const unsigned char *b
static int cyberjack_write_room( struct usb_serial_port *port )
{
+ /* FIXME: .... */
return CYBERJACK_LOCAL_BUF_SIZE;
}
@@ -314,7 +315,7 @@ static void cyberjack_read_int_callback( struct urb *urb )
usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length, data);
/* React only to interrupts signaling a bulk_in transfer */
- if( (urb->actual_length==4) && (data[0]==0x01) ) {
+ if( (urb->actual_length == 4) && (data[0] == 0x01) ) {
short old_rdtodo;
/* This is a announcement of coming bulk_ins. */
@@ -450,8 +451,8 @@ static void cyberjack_write_bulk_callback (struct urb *urb)
if (result) {
err("%s - failed submitting write urb, error %d", __func__, result);
/* Throw away data. No better idea what to do with it. */
- priv->wrfilled=0;
- priv->wrsent=0;
+ priv->wrfilled = 0;
+ priv->wrsent = 0;
goto exit;
}
@@ -463,8 +464,8 @@ static void cyberjack_write_bulk_callback (struct urb *urb)
if( (priv->wrsent>=priv->wrfilled) || (priv->wrsent>=blksize) ) {
dbg("%s - buffer cleaned", __func__);
memset( priv->wrbuf, 0, sizeof(priv->wrbuf) );
- priv->wrfilled=0;
- priv->wrsent=0;
+ priv->wrfilled = 0;
+ priv->wrsent = 0;
}
}
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 2078667db4a..65765ce7625 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -262,13 +262,14 @@ int usb_serial_generic_write_room (struct usb_serial_port *port)
dbg("%s - port %d", __func__, port->number);
+ /* FIXME: Locking */
if (serial->num_bulk_out) {
if (!(port->write_urb_busy))
room = port->bulk_out_size;
}
dbg("%s - returns %d", __func__, room);
- return (room);
+ return room;
}
int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
@@ -278,6 +279,7 @@ int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
dbg("%s - port %d", __func__, port->number);
+ /* FIXME: Locking */
if (serial->num_bulk_out) {
if (port->write_urb_busy)
chars = port->write_urb->transfer_buffer_length;
@@ -368,7 +370,6 @@ void usb_serial_generic_write_bulk_callback (struct urb *urb)
__func__, status);
return;
}
-
usb_serial_port_softint(port);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
index 857c5312555..0d122feb2b2 100644
--- a/drivers/usb/serial/keyspan.c
+++ b/drivers/usb/serial/keyspan.c
@@ -1187,6 +1187,7 @@ static int keyspan_write_room (struct usb_serial_port *port)
p_priv = usb_get_serial_port_data(port);
d_details = p_priv->device_details;
+ /* FIXME: locking */
if (d_details->msg_format == msg_usa90)
data_len = 64;
else
@@ -1203,13 +1204,13 @@ static int keyspan_write_room (struct usb_serial_port *port)
if (this_urb->status != -EINPROGRESS)
return (data_len);
}
- return (0);
+ return 0;
}
static int keyspan_chars_in_buffer (struct usb_serial_port *port)
{
- return (0);
+ return 0;
}
@@ -1289,7 +1290,7 @@ static int keyspan_open (struct usb_serial_port *port, struct file *filp)
//mdelay(100);
//keyspan_set_termios(port, NULL);
- return (0);
+ return 0;
}
static inline void stop_urb(struct urb *urb)
@@ -2006,7 +2007,7 @@ static int keyspan_usa26_send_setup(struct usb_serial *serial,
}
#endif
- return (0);
+ return 0;
}
static int keyspan_usa28_send_setup(struct usb_serial *serial,
@@ -2131,7 +2132,7 @@ static int keyspan_usa28_send_setup(struct usb_serial *serial,
}
#endif
- return (0);
+ return 0;
}
static int keyspan_usa49_send_setup(struct usb_serial *serial,
@@ -2317,7 +2318,7 @@ static int keyspan_usa49_send_setup(struct usb_serial *serial,
}
#endif
- return (0);
+ return 0;
}
static int keyspan_usa90_send_setup(struct usb_serial *serial,
@@ -2455,7 +2456,7 @@ static int keyspan_usa90_send_setup(struct usb_serial *serial,
if ((err = usb_submit_urb(this_urb, GFP_ATOMIC)) != 0) {
dbg("%s - usb_submit_urb(setup) failed (%d)", __func__, err);
}
- return (0);
+ return 0;
}
static int keyspan_usa67_send_setup(struct usb_serial *serial,
@@ -2603,7 +2604,7 @@ static int keyspan_usa67_send_setup(struct usb_serial *serial,
if (err != 0)
dbg("%s - usb_submit_urb(setup) failed (%d)", __func__,
err);
- return (0);
+ return 0;
}
static void keyspan_send_setup(struct usb_serial_port *port, int reset_port)
@@ -2696,7 +2697,7 @@ static int keyspan_startup (struct usb_serial *serial)
err);
}
- return (0);
+ return 0;
}
static void keyspan_shutdown (struct usb_serial *serial)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 6ce292ef1c4..b650fb4754b 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -636,14 +636,19 @@ static int keyspan_pda_write_room (struct usb_serial_port *port)
static int keyspan_pda_chars_in_buffer (struct usb_serial_port *port)
{
struct keyspan_pda_private *priv;
+ unsigned long flags;
+ int ret = 0;
priv = usb_get_serial_port_data(port);
/* when throttled, return at least WAKEUP_CHARS to tell select() (via
n_tty.c:normal_poll() ) that we're not writeable. */
+
+ spin_lock_irqsave(&port->lock, flags);
if (port->write_urb_busy || priv->tx_throttled)
- return 256;
- return 0;
+ ret = 256;
+ spin_unlock_irqrestore(&port->lock, flags);
+ return ret;
}
diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index 160e19263e2..b3ac045ab40 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -702,12 +702,14 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
struct ktermios *old_termios)
{
struct klsi_105_private *priv = usb_get_serial_port_data(port);
- unsigned int iflag = port->tty->termios->c_iflag;
+ struct tty_struct *tty = port->tty;
+ unsigned int iflag = tty->termios->c_iflag;
unsigned int old_iflag = old_termios->c_iflag;
- unsigned int cflag = port->tty->termios->c_cflag;
+ unsigned int cflag = tty->termios->c_cflag;
unsigned int old_cflag = old_termios->c_cflag;
struct klsi_105_port_settings cfg;
unsigned long flags;
+ speed_t baud;
/* lock while we are modifying the settings */
spin_lock_irqsave (&priv->lock, flags);
@@ -715,6 +717,8 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
/*
* Update baud rate
*/
+ baud = tty_get_baud_rate(tty);
+
if( (cflag & CBAUD) != (old_cflag & CBAUD) ) {
/* reassert DTR and (maybe) RTS on transition from B0 */
if( (old_cflag & CBAUD) == B0 ) {
@@ -728,8 +732,8 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
mct_u232_set_modem_ctrl(serial, priv->control_state);
#endif
}
-
- switch(tty_get_baud_rate(port->tty)) {
+ }
+ switch(baud) {
case 0: /* handled below */
break;
case 1200:
@@ -757,25 +761,26 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
priv->cfg.baudrate = kl5kusb105a_sio_b115200;
break;
default:
- err("KLSI USB->Serial converter:"
+ dbg("KLSI USB->Serial converter:"
" unsupported baudrate request, using default"
" of 9600");
priv->cfg.baudrate = kl5kusb105a_sio_b9600;
+ baud = 9600;
break;
- }
- if ((cflag & CBAUD) == B0 ) {
- dbg("%s: baud is B0", __func__);
- /* Drop RTS and DTR */
- /* maybe this should be simulated by sending read
- * disable and read enable messages?
- */
- ;
+ }
+ if ((cflag & CBAUD) == B0 ) {
+ dbg("%s: baud is B0", __func__);
+ /* Drop RTS and DTR */
+ /* maybe this should be simulated by sending read
+ * disable and read enable messages?
+ */
+ ;
#if 0
- priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
- mct_u232_set_modem_ctrl(serial, priv->control_state);
+ priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
+ mct_u232_set_modem_ctrl(serial, priv->control_state);
#endif
- }
}
+ tty_encode_baud_rate(tty, baud, baud);
if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
/* set the number of data bits */
@@ -807,6 +812,8 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
|| (cflag & CSTOPB) != (old_cflag & CSTOPB) ) {
+ /* Not currently supported */
+ tty->termios->c_cflag &= ~(PARENB|PARODD|CSTOPB);
#if 0
priv->last_lcr = 0;
@@ -834,6 +841,8 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
|| (iflag & IXON) != (old_iflag & IXON)
|| (cflag & CRTSCTS) != (old_cflag & CRTSCTS) ) {
+ /* Not currently supported */
+ tty->termios->c_cflag &= ~CRTSCTS;
/* Drop DTR/RTS if no flow control otherwise assert */
#if 0
if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS) )
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 74b889bf19c..50f1fe26333 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -635,6 +635,7 @@ static int mos7720_write_room(struct usb_serial_port *port)
return -ENODEV;
}
+ /* FIXME: Locking */
for (i = 0; i < NUM_URBS; ++i) {
if (mos7720_port->write_urb_pool[i] && mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
room += URB_TRANSFER_BUFFER_SIZE;
diff --git a/drivers/usb/serial/navman.c b/drivers/usb/serial/navman.c
index 7cea325d577..43c8894353b 100644
--- a/drivers/usb/serial/navman.c
+++ b/drivers/usb/serial/navman.c
@@ -6,6 +6,10 @@
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
+ *
+ * TODO:
+ * Add termios method that uses copy_hw but also kills all echo
+ * flags as the navman is rx only so cannot echo.
*/
#include <linux/kernel.h>
@@ -106,12 +110,8 @@ static int navman_write(struct usb_serial_port *port,
/*
* This device can't write any data, only read from the device
- * so we just silently eat all data sent to us and say it was
- * successfully sent.
- * Evil, I know, but do you have a better idea?
*/
-
- return count;
+ return -EOPNOTSUPP;
}
static struct usb_serial_driver navman_device = {
diff --git a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c
index 1b041c59aab..10090cb52d3 100644
--- a/drivers/usb/serial/omninet.c
+++ b/drivers/usb/serial/omninet.c
@@ -295,8 +295,9 @@ static int omninet_write_room (struct usb_serial_port *port)
struct usb_serial *serial = port->serial;
struct usb_serial_port *wport = serial->port[1];
- int room = 0; // Default: no room
+ int room = 0; /* Default: no room */
+ /* FIXME: no consistent locking for write_urb_busy */
if (wport->write_urb_busy)
room = wport->bulk_out_size - OMNINET_HEADERLEN;
diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index 920241897c9..a83892627d6 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -656,6 +656,7 @@ static int option_write_room(struct usb_serial_port *port)
portdata = usb_get_serial_port_data(port);
+
for (i=0; i < N_OUT_URB; i++) {
this_urb = portdata->out_urbs[i];
if (this_urb && !test_bit(i, &portdata->out_busy))
@@ -677,6 +678,8 @@ static int option_chars_in_buffer(struct usb_serial_port *port)
for (i=0; i < N_OUT_URB; i++) {
this_urb = portdata->out_urbs[i];
+ /* FIXME: This locking is insufficient as this_urb may
+ go unused during the test */
if (this_urb && test_bit(i, &portdata->out_busy))
data_len += this_urb->transfer_buffer_length;
}
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 2b4ab371c76..c60930ec934 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -546,6 +546,8 @@ static void pl2303_set_termios(struct usb_serial_port *port,
buf = kzalloc(7, GFP_KERNEL);
if (!buf) {
dev_err(&port->dev, "%s - out of memory.\n", __func__);
+ /* Report back no change occurred */
+ *port->tty->termios = *old_termios;
return;
}
diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c
index 3fe98a52b91..e6acac49a9c 100644
--- a/drivers/usb/serial/safe_serial.c
+++ b/drivers/usb/serial/safe_serial.c
@@ -198,7 +198,6 @@ static void safe_read_bulk_callback (struct urb *urb)
struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
unsigned char *data = urb->transfer_buffer;
unsigned char length = urb->actual_length;
- int i;
int result;
int status = urb->status;
@@ -227,16 +226,10 @@ static void safe_read_bulk_callback (struct urb *urb)
if (safe) {
__u16 fcs;
if (!(fcs = fcs_compute10 (data, length, CRC10_INITFCS))) {
-
int actual_length = data[length - 2] >> 2;
-
if (actual_length <= (length - 2)) {
-
info ("%s - actual: %d", __func__, actual_length);
-
- for (i = 0; i < actual_length; i++) {
- tty_insert_flip_char (port->tty, data[i], 0);
- }
+ tty_insert_flip_string(port->tty, data, actual_length);
tty_flip_buffer_push (port->tty);
} else {
err ("%s - inconsistent lengths %d:%d", __func__,
@@ -246,9 +239,7 @@ static void safe_read_bulk_callback (struct urb *urb)
err ("%s - bad CRC %x", __func__, fcs);
}
} else {
- for (i = 0; i < length; i++) {
- tty_insert_flip_char (port->tty, data[i], 0);
- }
+ tty_insert_flip_string(port->tty, data, length);
tty_flip_buffer_push (port->tty);
}
@@ -260,6 +251,7 @@ static void safe_read_bulk_callback (struct urb *urb)
if ((result = usb_submit_urb (urb, GFP_ATOMIC))) {
err ("%s - failed resubmitting read urb, error %d", __func__, result);
+ /* FIXME: Need a mechanism to retry later if this happens */
}
}
@@ -275,7 +267,7 @@ static int safe_write (struct usb_serial_port *port, const unsigned char *buf, i
if (!port->write_urb) {
dbg ("%s - write urb NULL", __func__);
- return (0);
+ return 0;
}
dbg ("safe_write write_urb: %d transfer_buffer_length",
@@ -283,11 +275,11 @@ static int safe_write (struct usb_serial_port *port, const unsigned char *buf, i
if (!port->write_urb->transfer_buffer_length) {
dbg ("%s - write urb transfer_buffer_length zero", __func__);
- return (0);
+ return 0;
}
if (count == 0) {
dbg ("%s - write request of 0 bytes", __func__);
- return (0);
+ return 0;
}
spin_lock_bh(&port->lock);
if (port->write_urb_busy) {
@@ -359,18 +351,21 @@ static int safe_write (struct usb_serial_port *port, const unsigned char *buf, i
static int safe_write_room (struct usb_serial_port *port)
{
- int room = 0; // Default: no room
+ int room = 0; /* Default: no room */
+ unsigned long flags;
dbg ("%s", __func__);
+ spin_lock_irqsave(&port->lock, flags);
if (port->write_urb_busy)
room = port->bulk_out_size - (safe ? 2 : 0);
+ spin_unlock_irqrestore(&port->lock, flags);
if (room) {
dbg ("safe_write_room returns %d", room);
}
- return (room);
+ return room;
}
static int safe_startup (struct usb_serial *serial)
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index ed30adefff8..23188873eb0 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -566,6 +566,8 @@ static int sierra_chars_in_buffer(struct usb_serial_port *port)
* have sent out, but hasn't made it through to the
* device as we can't see the backend here, so just
* tell the tty layer that everything is flushed.
+ *
+ * FIXME: should walk the outstanding urbs info
*/
return 0;
}
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index baf953d14d8..a9934a3f984 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1179,6 +1179,8 @@ static int __init usb_serial_init(void)
usb_serial_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
usb_serial_tty_driver->init_termios = tty_std_termios;
usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+ usb_serial_tty_driver->init_termios.c_ispeed = 9600;
+ usb_serial_tty_driver->init_termios.c_ospeed = 9600;
tty_set_operations(usb_serial_tty_driver, &serial_ops);
result = tty_register_driver(usb_serial_tty_driver);
if (result) {
diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
index 137df445e29..a100a52a376 100644
--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c
@@ -469,6 +469,8 @@ static int visor_chars_in_buffer (struct usb_serial_port *port)
* have sent out, but hasn't made it through to the
* device, so just tell the tty layer that everything
* is flushed.
+ *
+ * FIXME: Should walk outstanding_urbs
*/
return 0;
}
diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index fb02424de4a..6926a81a0cc 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -219,7 +219,7 @@ struct whiteheat_urb_wrap {
struct whiteheat_private {
spinlock_t lock;
__u8 flags;
- __u8 mcr;
+ __u8 mcr; /* FIXME: no locking on mcr */
struct list_head rx_urbs_free;
struct list_head rx_urbs_submitted;
struct list_head rx_urb_q;