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author | Ian Abbott | 2015-03-27 16:13:04 +0100 |
---|---|---|
committer | Greg Kroah-Hartman | 2015-04-03 13:11:53 +0200 |
commit | 922d9ced718268e464a0884ecee09da436e00d70 (patch) | |
tree | e07d77959f714b49f212b602841d78d94b55e780 /drivers/staging/comedi/comedi_fops.c | |
parent | staging: comedi: comedi_fops: remove unnecessary s->async use (diff) | |
download | kernel-qcow2-linux-922d9ced718268e464a0884ecee09da436e00d70.tar.gz kernel-qcow2-linux-922d9ced718268e464a0884ecee09da436e00d70.tar.xz kernel-qcow2-linux-922d9ced718268e464a0884ecee09da436e00d70.zip |
staging: comedi: comedi_fops: always clear events
`comedi_event()` is called from low-level drivers to handle asynchronous
command event flags that are stored in `s->async->events` for subdevice
`s`. It normally clears the event flags as well. As a safety check, it
does nothing if no asynchronous command is running, but it leaves
`s->async->events` unchanged in this case. For additional safety,
change it to always clear the event flags to avoid leaving stale event
flags set when another asynchronous command is set up.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/comedi/comedi_fops.c')
-rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 999e7d010c83..68ced20f5ca5 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2648,18 +2648,20 @@ void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s) struct comedi_async *async = s->async; unsigned runflags = 0; unsigned runflags_mask = 0; + unsigned int events = async->events; + async->events = 0; if (!comedi_is_subdevice_running(s)) return; - if (async->events & COMEDI_CB_CANCEL_MASK) + if (events & COMEDI_CB_CANCEL_MASK) runflags_mask |= COMEDI_SRF_RUNNING; /* * Remember if an error event has occurred, so an error * can be returned the next time the user does a read(). */ - if (async->events & COMEDI_CB_ERROR_MASK) { + if (events & COMEDI_CB_ERROR_MASK) { runflags_mask |= COMEDI_SRF_ERROR; runflags |= COMEDI_SRF_ERROR; } @@ -2671,14 +2673,13 @@ void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s) comedi_update_subdevice_runflags(s, runflags_mask, runflags); } - if (async->cb_mask & async->events) { + if (async->cb_mask & events) { wake_up_interruptible(&async->wait_head); if (s->subdev_flags & SDF_CMD_READ) kill_fasync(&dev->async_queue, SIGIO, POLL_IN); if (s->subdev_flags & SDF_CMD_WRITE) kill_fasync(&dev->async_queue, SIGIO, POLL_OUT); } - async->events = 0; } EXPORT_SYMBOL_GPL(comedi_event); |