staging: comedi: addi_apci_2032: 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 immediatelt 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@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/addi_apci_2032.c b/drivers/staging/comedi/drivers/addi_apci_2032.c
index 45ea4a4e451bb4a75a7a81bc2c71f5a6a848e857..8514811a988b0996f807f1e933d42af512d1e158 100644 (file)
--- a/drivers/staging/comedi/drivers/addi_apci_2032.c
+++ b/drivers/staging/comedi/drivers/addi_apci_2032.c
@@ -96,16 +96,9 @@ static bool apci2032_int_start(struct comedi_device *dev,
 
        subpriv->enabled_isns = enabled_isns;
        subpriv->stop_count = cmd->stop_arg;
-       if (cmd->stop_src == TRIG_COUNT && subpriv->stop_count == 0) {
-               /* An empty acquisition! */
-               s->async->events |= COMEDI_CB_EOA;
-               subpriv->active = false;
-               do_event = true;
-       } else {
-               subpriv->active = true;
-               outl(enabled_isns, dev->iobase + APCI2032_INT_CTRL_REG);
-               do_event = false;
-       }
+       subpriv->active = true;
+       outl(enabled_isns, dev->iobase + APCI2032_INT_CTRL_REG);
+       do_event = false;
 
        return do_event;
 }
@@ -141,7 +134,9 @@ static int apci2032_int_cmdtest(struct comedi_device *dev,
        err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
        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)