diff options
| author | Bjørn Mork <bjorn@mork.no> | 2012-07-27 01:11:42 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-10 11:51:43 -0700 |
| commit | d5fd650cfc7ffeca4af0da939293c8e7a5aa7c36 (patch) | |
| tree | 1f005c3c25a7d75d2cf4abc01f566efa23f9425a /drivers | |
| parent | a1028f0abfb321e0f87c10ac0cce8508097c2b42 (diff) | |
| download | lwn-d5fd650cfc7ffeca4af0da939293c8e7a5aa7c36.tar.gz lwn-d5fd650cfc7ffeca4af0da939293c8e7a5aa7c36.zip | |
usb: serial: prevent suspend/resume from racing against probe/remove
Some usb-serial drivers may access port data in their suspend/
resume functions. Such drivers must always verify the validity
of the data as both suspend and resume can be called both before
usb_serial_device_probe and after usb_serial_device_remove.
But the port data may be invalidated during port_probe and
port_remove. This patch prevents the race against suspend and
resume by disabling suspend while port_probe or port_remove is
running.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/serial/bus.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/usb/serial/bus.c b/drivers/usb/serial/bus.c index f398d1e34474..c15f2e7cefc7 100644 --- a/drivers/usb/serial/bus.c +++ b/drivers/usb/serial/bus.c @@ -61,18 +61,23 @@ static int usb_serial_device_probe(struct device *dev) goto exit; } + /* make sure suspend/resume doesn't race against port_probe */ + retval = usb_autopm_get_interface(port->serial->interface); + if (retval) + goto exit; + driver = port->serial->type; if (driver->port_probe) { retval = driver->port_probe(port); if (retval) - goto exit; + goto exit_with_autopm; } retval = device_create_file(dev, &dev_attr_port_number); if (retval) { if (driver->port_remove) retval = driver->port_remove(port); - goto exit; + goto exit_with_autopm; } minor = port->number; @@ -81,6 +86,8 @@ static int usb_serial_device_probe(struct device *dev) "%s converter now attached to ttyUSB%d\n", driver->description, minor); +exit_with_autopm: + usb_autopm_put_interface(port->serial->interface); exit: return retval; } @@ -96,6 +103,9 @@ static int usb_serial_device_remove(struct device *dev) if (!port) return -ENODEV; + /* make sure suspend/resume doesn't race against port_remove */ + usb_autopm_get_interface(port->serial->interface); + device_remove_file(&port->dev, &dev_attr_port_number); driver = port->serial->type; @@ -107,6 +117,7 @@ static int usb_serial_device_remove(struct device *dev) dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", driver->description, minor); + usb_autopm_put_interface(port->serial->interface); return retval; } |