During the 2.6.32 development usb serial tty interface was changed.
This change caused the usb serial driver to crash when used as a
system console.
The open and close of the raw hardware has to be protected by the
serial->console variable so either the console code does the open and
close or the higher level tty based driver executes the open and
close.
* In serial_open() the raw open must be protected by serial->console
* In serial_down() the test_and_clear_bit must be executed before
leaving the function if the device is a serial console
* serial_release() should no longer protect for the console condition
due to the 2.6.32 interface changes. The actual low level close
protection is accounted for in serial_down()
Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/serial/usb-serial.c | 28 +++++++++++++---------------
1 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index ff75a35..3d35ed2 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -267,10 +267,14 @@ static int serial_open(struct tty_struct *tty, struct file *filp)
if (mutex_lock_interruptible(&port->mutex))
return -ERESTARTSYS;
mutex_lock(&serial->disc_mutex);
- if (serial->disconnected)
+ if (serial->disconnected) {
retval = -ENODEV;
- else
- retval = port->serial->type->open(tty, port);
+ } else {
+ if (port->console)
+ retval = 0;
+ else
+ retval = port->serial->type->open(tty, port);
+ }
mutex_unlock(&serial->disc_mutex);
mutex_unlock(&port->mutex);
if (retval)
@@ -294,6 +298,12 @@ static void serial_down(struct usb_serial_port *port)
{
struct usb_serial_driver *drv = port->serial->type;
+ /* Don't call the close method if the hardware hasn't been
+ * initialized.
+ */
+ if (!test_and_clear_bit(ASYNCB_INITIALIZED, &port->port.flags))
+ return;
+
/*
* The console is magical. Do not hang up the console hardware
* or there will be tears.
@@ -301,12 +311,6 @@ static void serial_down(struct usb_serial_port *port)
if (port->console)
return;
- /* Don't call the close method if the hardware hasn't been
- * initialized.
- */
- if (!test_and_clear_bit(ASYNCB_INITIALIZED, &port->port.flags))
- return;
-
mutex_lock(&port->mutex);
if (drv->close)
drv->close(port);
@@ -353,12 +357,6 @@ static void serial_release(struct tty_struct *tty)
struct usb_serial *serial;
struct module *owner;
- /* The console is magical. Do not hang up the console hardware
- * or there will be tears.
- */
- if (port->console)
- return;
-
dbg("%s - port %d", __func__, port->number);
/* Standard shutdown processing */
--
1.6.4.rc1
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
