From c5d9973b046fb8e0b0f3a8ad925d0033eec59856 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 9 Sep 2014 16:15:45 -0700 Subject: [PATCH] staging: comedi: cb_pcidas: 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 --- drivers/staging/comedi/drivers/cb_pcidas.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c index 961903e1860d..1ec363b7505c 100644 --- a/drivers/staging/comedi/drivers/cb_pcidas.c +++ b/drivers/staging/comedi/drivers/cb_pcidas.c @@ -886,7 +886,9 @@ static int cb_pcidas_ai_cmdtest(struct comedi_device *dev, 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) @@ -1079,7 +1081,9 @@ static int cb_pcidas_ao_cmdtest(struct comedi_device *dev, 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) -- 2.34.1