staging: comedi: ni_pcidio: prevent "empty acquisition" async command

This driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".

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>
This commit is contained in:
H Hartley Sweeten 2014-09-09 16:15:51 -07:00 committed by Greg Kroah-Hartman
parent fd6887b2ec
commit 7be7f9c3e3
1 changed files with 3 additions and 4 deletions

View File

@ -598,11 +598,10 @@ static int ni_pcidio_cmdtest(struct comedi_device *dev,
err |= cfc_check_trigger_arg_is(&cmd->convert_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); err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
if (cmd->stop_src == TRIG_COUNT) { if (cmd->stop_src == TRIG_COUNT)
/* no limit */ err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1);
} else { /* TRIG_NONE */ else /* TRIG_NONE */
err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0); err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
}
if (err) if (err)
return 3; return 3;