staging: comedi: dt2814: tidy up the irq support in dt2814_attach()

An irq is only needed by this driver in order to support async commands.
Since it is optional, modify the attach so that if the request_irq() fails
the attach does not fail.

Remove the printk noise about the irq.

Only hookup the async command support if the request_irq() was successful.

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>

1 files changed, 15 insertions, 18 deletions

diff --git a/drivers/staging/comedi/drivers/dt2814.c b/drivers/staging/comedi/drivers/dt2814.c
index c3f82087ae10..e52d22e0ba63 100644
--- a/drivers/staging/comedi/drivers/dt2814.c
+++ b/drivers/staging/comedi/drivers/dt2814.c
@@ -235,9 +235,9 @@ static irqreturn_t dt2814_interrupt(int irq, void *d)
 static int dt2814_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
         struct dt2814_private *devpriv;
-        int i, irq;
-        int ret;
         struct comedi_subdevice *s;
+        int ret;
+        int i;
 
         ret = comedi_request_region(dev, it->options[0], DT2814_SIZE);
         if (ret)
@@ -252,17 +252,11 @@ static int dt2814_attach(struct comedi_device *dev, struct comedi_devconfig *it)
         i = inb(dev->iobase + DT2814_DATA);
         i = inb(dev->iobase + DT2814_DATA);
 
-        irq = it->options[1];
-        dev->irq = 0;
-        if (irq > 0) {
-                if (request_irq(irq, dt2814_interrupt, 0, "dt2814", dev)) {
-                        printk(KERN_WARNING "(irq %d unavailable)\n", irq);
-                } else {
-                        printk(KERN_INFO "( irq = %d )\n", irq);
-                        dev->irq = irq;
-                }
-        } else if (irq == 0) {
-                printk(KERN_WARNING "(no irq)\n");
+        if (it->options[1]) {
+                ret = request_irq(it->options[1], dt2814_interrupt, 0,
+                                  dev->board_name, dev);
+                if (ret == 0)
+                        dev->irq = it->options[1];
         }
 
         ret = comedi_alloc_subdevices(dev, 1);
@@ -274,16 +268,19 @@ static int dt2814_attach(struct comedi_device *dev, struct comedi_devconfig *it)
                 return -ENOMEM;
 
         s = &dev->subdevices[0];
-        dev->read_subdev = s;
         s->type = COMEDI_SUBD_AI;
-        s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
+        s->subdev_flags = SDF_READABLE | SDF_GROUND;
         s->n_chan = 16;         /* XXX */
-        s->len_chanlist = 1;
         s->insn_read = dt2814_ai_insn_read;
-        s->do_cmd = dt2814_ai_cmd;
-        s->do_cmdtest = dt2814_ai_cmdtest;
         s->maxdata = 0xfff;
         s->range_table = &range_unknown;        /* XXX */
+        if (dev->irq) {
+                dev->read_subdev = s;
+                s->subdev_flags |= SDF_CMD_READ;
+                s->len_chanlist = 1;
+                s->do_cmd = dt2814_ai_cmd;
+                s->do_cmdtest = dt2814_ai_cmdtest;
+        }
 
         return 0;
 }