From 54d2925bd6b49b5330e8ebbdc83416b0b1605fa2 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 9 Sep 2014 16:15:41 -0700 Subject: [PATCH] staging: comedi: amplc_pci230: remove analog output "empty acquisition" async command This driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event without acquiring any data. This "empty acquisition" async command is not really useful. Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition" code. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/amplc_pci230.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/staging/comedi/drivers/amplc_pci230.c b/drivers/staging/comedi/drivers/amplc_pci230.c index e9ca1745f0c9..886186d00d4d 100644 --- a/drivers/staging/comedi/drivers/amplc_pci230.c +++ b/drivers/staging/comedi/drivers/amplc_pci230.c @@ -987,7 +987,9 @@ static int pci230_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) @@ -1255,13 +1257,7 @@ static void pci230_ao_start(struct comedi_device *dev, unsigned long irqflags; devpriv->ao_cmd_started = true; - if (cmd->stop_src == TRIG_COUNT && devpriv->ao_scan_count == 0) { - /* An empty acquisition! */ - async->events |= COMEDI_CB_EOA; - pci230_ao_stop(dev, s); - comedi_event(dev, s); - return; - } + if (devpriv->hwver >= 2) { /* Using DAC FIFO. */ unsigned short scantrig; -- 2.30.2