From 7be7f9c3e3f87fd1263014a14b177409b6542e54 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 9 Sep 2014 16:15:51 -0700 Subject: [PATCH] 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 Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ni_pcidio.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_pcidio.c b/drivers/staging/comedi/drivers/ni_pcidio.c index ede8e4117ab3..5252cba82e5e 100644 --- a/drivers/staging/comedi/drivers/ni_pcidio.c +++ b/drivers/staging/comedi/drivers/ni_pcidio.c @@ -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->scan_end_arg, cmd->chanlist_len); - if (cmd->stop_src == TRIG_COUNT) { - /* no limit */ - } else { /* 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) return 3; -- 2.20.1