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USB: usb-serial: call port_probe and port_remove at the right times 

This patch (as1253) prevents the usb-serial core from calling a
driver's port_probe and port_remove methods more than once per port.
It also removes some unnecessary try_module_get() calls and adds a
missing port_remove method call in a failure path.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2009-06-02 11:54:11 -04:00 committed by Greg Kroah-Hartman
parent c6994e6f06
commit c706ebdfc8
3 changed files with 41 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/usb/serial/bus.c
View File

@ -59,23 +59,22 @@ static int usb_serial_device_probe(struct device *dev)
retval = -ENODEV;
goto exit;
}
if (port->dev_state != PORT_REGISTERING)
goto exit;
driver = port->serial->type;
if (driver->port_probe) {
if (!try_module_get(driver->driver.owner)) {
dev_err(dev, "module get failed, exiting\n");
retval = -EIO;
goto exit;
}
retval = driver->port_probe(port);
module_put(driver->driver.owner);
if (retval)
goto exit;
}
retval = device_create_file(dev, &dev_attr_port_number);
if (retval)
if (retval) {
if (driver->port_remove)
retval = driver->port_remove(port);
goto exit;
}
minor = port->number;
tty_register_device(usb_serial_tty_driver, minor, dev);
@ -98,19 +97,15 @@ static int usb_serial_device_remove(struct device *dev)
if (!port)
return -ENODEV;
if (port->dev_state != PORT_UNREGISTERING)
return retval;
device_remove_file(&port->dev, &dev_attr_port_number);
driver = port->serial->type;
if (driver->port_remove) {
if (!try_module_get(driver->driver.owner)) {
dev_err(dev, "module get failed, exiting\n");
retval = -EIO;
goto exit;
}
if (driver->port_remove)
retval = driver->port_remove(port);
module_put(driver->driver.owner);
}
exit:
minor = port->number;
tty_unregister_device(usb_serial_tty_driver, minor);
dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",

24
drivers/usb/serial/usb-serial.c
View File

@ -1046,10 +1046,15 @@ int usb_serial_probe(struct usb_interface *interface,
dev_set_name(&port->dev, "ttyUSB%d", port->number);
dbg ("%s - registering %s", __func__, dev_name(&port->dev));
port->dev_state = PORT_REGISTERING;
retval = device_register(&port->dev);
if (retval)
if (retval) {
dev_err(&port->dev, "Error registering port device, "
"continuing\n");
port->dev_state = PORT_UNREGISTERED;
} else {
port->dev_state = PORT_REGISTERED;
}
}
usb_serial_console_init(debug, minor);
@ -1130,7 +1135,22 @@ void usb_serial_disconnect(struct usb_interface *interface)
}
kill_traffic(port);
cancel_work_sync(&port->work);
device_del(&port->dev);
if (port->dev_state == PORT_REGISTERED) {
/* Make sure the port is bound so that the
* driver's port_remove method is called.
*/
if (!port->dev.driver) {
int rc;
port->dev.driver =
&serial->type->driver;
rc = device_bind_driver(&port->dev);
}
port->dev_state = PORT_UNREGISTERING;
device_del(&port->dev);
port->dev_state = PORT_UNREGISTERED;
}
}
}
serial->type->shutdown(serial);

8
include/linux/usb/serial.h
View File

@ -27,6 +27,13 @@
/* parity check flag */
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
enum port_dev_state {
PORT_UNREGISTERED,
PORT_REGISTERING,
PORT_REGISTERED,
PORT_UNREGISTERING,
};
/**
* usb_serial_port: structure for the specific ports of a device.
* @serial: pointer back to the struct usb_serial owner of this port.
@ -102,6 +109,7 @@ struct usb_serial_port {
char console;
unsigned long sysrq; /* sysrq timeout */
struct device dev;
enum port_dev_state dev_state;
};
#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)