staging: comedi: pcmuio: fix the cmd->start_arg use for TRIG_INT

This driver supports a cmd->start_src of TRIG_NOW or TRIG_INT. The
cmd->start_arg is trivially validated for both sources to be 0.

For a TRIG_INT source, the cmd->start_arg is actually the valid
trig_num that is used by the async (*inttrig) callback.

Refactor the (*inttrig) function so that the cmd->start_arg is used
to check the trig_num instead of the open coded value.

For aesthetics, refactor the (*do_cmd) to use if/else instead if the
switch when handling the cmd->start_src.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/pcmuio.c b/drivers/staging/comedi/drivers/pcmuio.c
index a8f390f..ea45424 100644 (file)
--- a/drivers/staging/comedi/drivers/pcmuio.c
+++ b/drivers/staging/comedi/drivers/pcmuio.c
@@ -460,20 +460,18 @@ static int pcmuio_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
        return 0;
 }
 
-/*
- * Internal trigger function to start acquisition for an 'INTERRUPT' subdevice.
- */
-static int
-pcmuio_inttrig_start_intr(struct comedi_device *dev, struct comedi_subdevice *s,
-                         unsigned int trignum)
+static int pcmuio_inttrig_start_intr(struct comedi_device *dev,
+                                    struct comedi_subdevice *s,
+                                    unsigned int trig_num)
 {
        struct pcmuio_private *devpriv = dev->private;
+       struct comedi_cmd *cmd = &s->async->cmd;
        int asic = pcmuio_subdevice_to_asic(s);
        struct pcmuio_asic *chip = &devpriv->asics[asic];
        unsigned long flags;
        int event = 0;
 
-       if (trignum != 0)
+       if (trig_num != cmd->start_arg)
                return -EINVAL;
 
        spin_lock_irqsave(&chip->spinlock, flags);
@@ -518,15 +516,11 @@ static int pcmuio_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
        }
 
        /* Set up start of acquisition. */
-       switch (cmd->start_src) {
-       case TRIG_INT:
+       if (cmd->start_src == TRIG_INT)
                s->async->inttrig = pcmuio_inttrig_start_intr;
-               break;
-       default:
-               /* TRIG_NOW */
+       else    /* TRIG_NOW */
                event = pcmuio_start_intr(dev, s);
-               break;
-       }
+
        spin_unlock_irqrestore(&chip->spinlock, flags);
 
        if (event)