From fe094b7e00b507e279782e0a319b7fb32e53d2d0 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 9 Sep 2014 16:15:52 -0700 Subject: [PATCH] staging: comedi: pcl711: remove "empty acquisition" async command 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 Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- 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 20ed09c..47f4887 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); -- 2.7.4