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@xxxxxxxxxxxxxxxxxxx> Cc: Ian Abbott <abbotti@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/comedi/drivers.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index e3bbc8f..44511d7 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -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) -- 2.6.3 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel