From: H Hartley Sweeten Date: Tue, 9 Sep 2014 23:15:48 +0000 (-0700) Subject: staging: comedi: dt282x: prevent "empty acquisition" async commands X-Git-Tag: v3.18-rc1~130^2~501 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=759658ddff327675bbf35063e2b04e0d7424124d;p=karo-tx-linux.git staging: comedi: dt282x: prevent "empty acquisition" async commands This driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg of 0 for both the analog input and output async commands. The (*do_cmd) for both subdevices sets up and starts the command without handling the "empty acquisition". This results in the interrupt functions 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 Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c index e725e3bf1532..cc974a5e5cf6 100644 --- a/drivers/staging/comedi/drivers/dt282x.c +++ b/drivers/staging/comedi/drivers/dt282x.c @@ -728,11 +728,10 @@ static int dt282x_ai_cmdtest(struct comedi_device *dev, err |= cfc_check_trigger_arg_min(&cmd->convert_arg, board->ai_speed); err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len); - if (cmd->stop_src == TRIG_COUNT) { - /* any count is allowed */ - } else { /* TRIG_NONE */ + if (cmd->stop_src == TRIG_COUNT) + err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1); + else /* TRIG_EXT | TRIG_NONE */ err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0); - } if (err) return 3; @@ -890,11 +889,10 @@ static int dt282x_ao_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_COUNT) { - /* any count is allowed */ - } else { /* TRIG_NONE */ + if (cmd->stop_src == TRIG_COUNT) + err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1); + else /* TRIG_EXT | TRIG_NONE */ err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0); - } if (err) return 3;