Hi,
this driver uses usb_get_intfdata() == NULL as a test for disconnect().
You must not do that as this races with probe(). By the time you test
your erstwhile interface may already be somebody else's interface.
This fixes the close() method of cypress_m8 to use the recently introduced
flag and use locking against disconnect() where required in close().
Signed-off-by: Oliver Neukum <[EMAIL PROTECTED]>
2.6.25 material
Regards
Oliver
----
--- linux-2.6.24-serial_intfdata/drivers/usb/serial/cypress_m8.c.alt
2008-01-22 15:24:31.000000000 +0100
+++ linux-2.6.24-serial_intfdata/drivers/usb/serial/cypress_m8.c
2008-01-22 15:24:35.000000000 +0100
@@ -682,7 +682,6 @@ static void cypress_close(struct usb_ser
{
struct cypress_private *priv = usb_get_serial_port_data(port);
unsigned int c_cflag;
- unsigned long flags;
int bps;
long timeout;
wait_queue_t wait;
@@ -690,7 +689,7 @@ static void cypress_close(struct usb_ser
dbg("%s - port %d", __FUNCTION__, port->number);
/* wait for data to drain from buffer */
- spin_lock_irqsave(&priv->lock, flags);
+ spin_lock_irq(&priv->lock);
timeout = CYPRESS_CLOSING_WAIT;
init_waitqueue_entry(&wait, current);
add_wait_queue(&port->tty->write_wait, &wait);
@@ -698,18 +697,25 @@ static void cypress_close(struct usb_ser
set_current_state(TASK_INTERRUPTIBLE);
if (cypress_buf_data_avail(priv->buf) == 0
|| timeout == 0 || signal_pending(current)
- || !usb_get_intfdata(port->serial->interface))
+ /* without mutex, allowed due to harmless failure mode */
+ || port->serial->disconnected)
break;
- spin_unlock_irqrestore(&priv->lock, flags);
+ spin_unlock_irq(&priv->lock);
timeout = schedule_timeout(timeout);
- spin_lock_irqsave(&priv->lock, flags);
+ spin_lock_irq(&priv->lock);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&port->tty->write_wait, &wait);
/* clear out any remaining data in the buffer */
cypress_buf_clear(priv->buf);
- spin_unlock_irqrestore(&priv->lock, flags);
-
+ spin_unlock_irq(&priv->lock);
+
+ /* writing is potentially harmful, lock must be taken */
+ mutex_lock(&port->serial->disc_mutex);
+ if (port->serial->disconnected) {
+ mutex_unlock(&port->serial->disc_mutex);
+ return;
+ }
/* wait for characters to drain from device */
bps = tty_get_baud_rate(port->tty);
if (bps > 1200)
@@ -727,10 +733,10 @@ static void cypress_close(struct usb_ser
if (c_cflag & HUPCL) {
/* drop dtr and rts */
priv = usb_get_serial_port_data(port);
- spin_lock_irqsave(&priv->lock, flags);
+ spin_lock_irq(&priv->lock);
priv->line_control = 0;
priv->cmd_ctrl = 1;
- spin_unlock_irqrestore(&priv->lock, flags);
+ spin_unlock_irq(&priv->lock);
cypress_write(port, NULL, 0);
}
}
@@ -738,6 +744,7 @@ static void cypress_close(struct usb_ser
if (stats)
dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out |
%d Commands Issued\n",
priv->bytes_in, priv->bytes_out, priv->cmd_count);
+ mutex_unlock(&port->serial->disc_mutex);
} /* cypress_close */
-
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