Commit 7be7cd10 authored Mar 30, 2016 by H Hartley Sweeten Committed by Greg Kroah-Hartman Mar 30, 2016

staging: comedi: drivers: fix possible bug in comedi_handle_events()



This function assumes that the async subdevice has a cancel() function.
It looks like all the current comedi drivers implement a cancel() for
the async subdevices except for the dt2814 analog input usbdevice.

Fix comedi_handle_events() so it does not try to call a non-existent
cancel() function.

Add a dev_warn() to __comedi_device_postconfig_async() so that any new
driver authors will be reminded to implement the cancel().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f91852ce

drivers/staging/comedi/drivers.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -564,7 +564,7 @@ unsigned int comedi_handle_events(struct comedi_device *dev,
		if (events == 0)
		return events;

		if (events & COMEDI_CB_CANCEL_MASK)
		if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel)
		s->cancel(dev, s);

		comedi_event(dev, s);
		@@ -625,6 +625,9 @@ static int __comedi_device_postconfig_async(struct comedi_device *dev,
		"async subdevices must have a do_cmdtest() function\n");
		return -EINVAL;
		}
		if (!s->cancel)
		dev_warn(dev->class_dev,
		"async subdevices should have a cancel() function\n");

		async = kzalloc(sizeof(*async), GFP_KERNEL);
		if (!async)