This driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.
This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/pcl711.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl711.c b/drivers/staging/comedi/drivers/pcl711.c
index 094e513..7b92a68 100644
--- a/drivers/staging/comedi/drivers/pcl711.c
+++ b/drivers/staging/comedi/drivers/pcl711.c
@@ -334,7 +334,9 @@ static int pcl711_ai_cmdtest(struct comedi_device *dev,
err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
- if (cmd->stop_src == TRIG_NONE)
+ if (cmd->stop_src == TRIG_COUNT)
+ err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1);
+ else /* TRIG_NONE */
err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
if (err)
@@ -376,15 +378,8 @@ static int pcl711_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
pcl711_set_changain(dev, s, cmd->chanlist[0]);
- if (cmd->stop_src == TRIG_COUNT) {
- if (cmd->stop_arg == 0) {
- /* an empty acquisition */
- s->async->events |= COMEDI_CB_EOA;
- comedi_event(dev, s);
- return 0;
- }
+ if (cmd->stop_src == TRIG_COUNT)
devpriv->ntrig = cmd->stop_arg;
- }
if (cmd->scan_begin_src == TRIG_TIMER) {
pcl711_ai_load_counters(dev);
--
2.0.3
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