staging: comedi: amplc_dio200_common: 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/amplc_dio200_common.c b/drivers/staging/comedi/drivers/amplc_dio200_common.c
index 6cadf7e..b13f9a2 100644 (file)
--- a/drivers/staging/comedi/drivers/amplc_dio200_common.c
+++ b/drivers/staging/comedi/drivers/amplc_dio200_common.c
@@ -217,28 +217,20 @@ static int dio200_start_intr(struct comedi_device *dev,
        struct comedi_cmd *cmd = &s->async->cmd;
        unsigned int n;
        unsigned isn_bits;
-       int retval = 0;
 
-       if (cmd->stop_src == TRIG_COUNT && subpriv->stopcount == 0) {
-               /* An empty acquisition! */
-               s->async->events |= COMEDI_CB_EOA;
-               subpriv->active = false;
-               retval = 1;
-       } else {
-               /* Determine interrupt sources to enable. */
-               isn_bits = 0;
-               if (cmd->chanlist) {
-                       for (n = 0; n < cmd->chanlist_len; n++)
-                               isn_bits |= (1U << CR_CHAN(cmd->chanlist[n]));
-               }
-               isn_bits &= subpriv->valid_isns;
-               /* Enable interrupt sources. */
-               subpriv->enabled_isns = isn_bits;
-               if (board->has_int_sce)
-                       dio200_write8(dev, subpriv->ofs, isn_bits);
+       /* Determine interrupt sources to enable. */
+       isn_bits = 0;
+       if (cmd->chanlist) {
+               for (n = 0; n < cmd->chanlist_len; n++)
+                       isn_bits |= (1U << CR_CHAN(cmd->chanlist[n]));
        }
+       isn_bits &= subpriv->valid_isns;
+       /* Enable interrupt sources. */
+       subpriv->enabled_isns = isn_bits;
+       if (board->has_int_sce)
+               dio200_write8(dev, subpriv->ofs, isn_bits);
 
-       return retval;
+       return 0;
 }
 
 static int dio200_inttrig_start_intr(struct comedi_device *dev,
@@ -425,16 +417,10 @@ static int dio200_subdev_intr_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);
 
-       switch (cmd->stop_src) {
-       case TRIG_COUNT:
-               /* any count allowed */
-               break;
-       case 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);
-               break;
-       default:
-               break;
-       }
 
        if (err)
                return 3;