staging: comedi: comedi_parport: don't fail attach if irq is not available

Interrupt support in this driver is optional. Don't fail the attach of the
board if the request_irq() fails.

Only allocate and setup the subdevice for the interrupt 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>

diff --git a/drivers/staging/comedi/drivers/comedi_parport.c b/drivers/staging/comedi/drivers/comedi_parport.c
index 33b3b90..f7680c9 100644 (file)
--- a/drivers/staging/comedi/drivers/comedi_parport.c
+++ b/drivers/staging/comedi/drivers/comedi_parport.c
@@ -250,25 +250,20 @@ static int parport_attach(struct comedi_device *dev,
                          struct comedi_devconfig *it)
 {
        struct comedi_subdevice *s;
-       unsigned int irq;
        int ret;
 
        ret = comedi_request_region(dev, it->options[0], 0x03);
        if (ret)
                return ret;
 
-       irq = it->options[1];
-       if (irq) {
-               ret = request_irq(irq, parport_interrupt, 0, dev->board_name,
-                                 dev);
-               if (ret < 0) {
-                       dev_err(dev->class_dev, "irq not available\n");
-                       return -EINVAL;
-               }
-               dev->irq = irq;
+       if (it->options[1]) {
+               ret = request_irq(it->options[1], parport_interrupt, 0,
+                                 dev->board_name, dev);
+               if (ret == 0)
+                       dev->irq = it->options[1];
        }
 
-       ret = comedi_alloc_subdevices(dev, 4);
+       ret = comedi_alloc_subdevices(dev, dev->irq ? 4 : 3);
        if (ret)
                return ret;
 
@@ -297,8 +292,8 @@ static int parport_attach(struct comedi_device *dev,
        s->range_table = &range_digital;
        s->insn_bits = parport_ctrl_reg_insn_bits;
 
-       s = &dev->subdevices[3];
-       if (irq) {
+       if (dev->irq) {
+               s = &dev->subdevices[3];
                dev->read_subdev = s;
                s->type = COMEDI_SUBD_DI;
                s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
@@ -309,8 +304,6 @@ static int parport_attach(struct comedi_device *dev,
                s->do_cmdtest = parport_intr_cmdtest;
                s->do_cmd = parport_intr_cmd;
                s->cancel = parport_intr_cancel;
-       } else {
-               s->type = COMEDI_SUBD_UNUSED;
        }
 
        outb(0, dev->iobase + PARPORT_DATA_REG);