From: H Hartley Sweeten Date: Wed, 30 Mar 2016 17:47:25 +0000 (-0700) Subject: staging: comedi: drivers: fix possible bug in comedi_handle_events() X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=7be7cd10ade121cd5363c5f8790638b177b5e9dd;p=deliverable%2Flinux.git 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 Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index e3bbc8f724ba..44511d729450 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)