From: H Hartley Sweeten Date: Tue, 9 Sep 2014 23:15:45 +0000 (-0700) Subject: staging: comedi: cb_pcidas: prevent "empty acquisition" async commands X-Git-Tag: v3.18-rc1~130^2~504 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c5d9973b046fb8e0b0f3a8ad925d0033eec59856;p=karo-tx-linux.git 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 --- 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)