summaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorBjørn Mork <bjorn@mork.no>2012-07-27 01:11:42 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-10 11:51:43 -0700
commitd5fd650cfc7ffeca4af0da939293c8e7a5aa7c36 (patch)
tree1f005c3c25a7d75d2cf4abc01f566efa23f9425a /drivers
parenta1028f0abfb321e0f87c10ac0cce8508097c2b42 (diff)
downloadop-kernel-dev-d5fd650cfc7ffeca4af0da939293c8e7a5aa7c36.zip
op-kernel-dev-d5fd650cfc7ffeca4af0da939293c8e7a5aa7c36.tar.gz
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.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/usb/serial/bus.c b/drivers/usb/serial/bus.c
index f398d1e..c15f2e7 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;
}
OpenPOWER on IntegriCloud