staging: comedi: rtd520: allow attaching without interrupt support

Interrupts ares only required for the ai subdevice command support.

Allow the driver to attach to the board even if request_irq() fails.
Only hook up the command support if the interrupt is available.

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

diff --git a/drivers/staging/comedi/drivers/rtd520.c b/drivers/staging/comedi/drivers/rtd520.c
index 3d68c4f..3c4aa65 100644 (file)
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -907,9 +907,6 @@ static int rtd_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
        writel(0, devpriv->las0 + LAS0_ADC_FIFO_CLEAR);
        writel(0, devpriv->las0 + LAS0_OVERRUN);
 
-       if (!dev->irq)  /* we need interrupts for this */
-               return -ENXIO;
-
        /* start configuration */
        /* load channel list and reset CGT */
        rtd_load_channelgain_list(dev, cmd->chanlist_len, cmd->chanlist);
@@ -1328,16 +1325,21 @@ static int rtd_attach_pci(struct comedi_device *dev, struct pci_dev *pcidev)
 
        rtd_pci_latency_quirk(dev, pcidev);
 
+       if (pcidev->irq) {
+               ret = request_irq(pcidev->irq, rtd_interrupt, IRQF_SHARED,
+                                 dev->board_name, dev);
+               if (ret == 0)
+                       dev->irq = pcidev->irq;
+       }
+
        ret = comedi_alloc_subdevices(dev, 4);
        if (ret)
                return ret;
 
        s = &dev->subdevices[0];
-       dev->read_subdev = s;
        /* analog input subdevice */
        s->type = COMEDI_SUBD_AI;
-       s->subdev_flags =
-           SDF_READABLE | SDF_GROUND | SDF_COMMON | SDF_DIFF | SDF_CMD_READ;
+       s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_COMMON | SDF_DIFF;
        s->n_chan = thisboard->aiChans;
        s->maxdata = (1 << thisboard->aiBits) - 1;
        if (thisboard->aiMaxGain <= 32)
@@ -1347,9 +1349,13 @@ static int rtd_attach_pci(struct comedi_device *dev, struct pci_dev *pcidev)
 
        s->len_chanlist = RTD_MAX_CHANLIST;     /* devpriv->fifoLen */
        s->insn_read = rtd_ai_rinsn;
-       s->do_cmd = rtd_ai_cmd;
-       s->do_cmdtest = rtd_ai_cmdtest;
-       s->cancel = rtd_ai_cancel;
+       if (dev->irq) {
+               dev->read_subdev = s;
+               s->subdev_flags |= SDF_CMD_READ;
+               s->do_cmd = rtd_ai_cmd;
+               s->do_cmdtest = rtd_ai_cmdtest;
+               s->cancel = rtd_ai_cancel;
+       }
 
        s = &dev->subdevices[1];
        /* analog output subdevice */
@@ -1381,13 +1387,6 @@ static int rtd_attach_pci(struct comedi_device *dev, struct pci_dev *pcidev)
 
        rtd_init_board(dev);
 
-       /* check if our interrupt is available and get it */
-       ret = request_irq(pcidev->irq, rtd_interrupt, IRQF_SHARED,
-                         dev->board_name, dev);
-       if (ret < 0)
-               return ret;
-       dev->irq = pcidev->irq;
-
        ret = rtd520_probe_fifo_depth(dev);
        if (ret < 0)
                return ret;