From 2c8af779c4c205ff379dcc3ac52831730ec0f5d5 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 9 Sep 2014 16:15:46 -0700 Subject: [PATCH] staging: comedi: das16: 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 Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das16.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c index baec9f2bd43c..2d8e86cec47a 100644 --- a/drivers/staging/comedi/drivers/das16.c +++ b/drivers/staging/comedi/drivers/das16.c @@ -692,7 +692,9 @@ static int das16_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s, err |= cfc_check_trigger_arg_min(&cmd->convert_arg, board->ai_speed); - 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) -- 2.20.1