On 2013-12-03 19:07, H Hartley Sweeten wrote:
Do the request_irq() before setting up the subdevices. This removes an
indent level and makes the code a bit cleaner.

Also, remove the dev_warn() noise about the irq.

Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
  drivers/staging/comedi/drivers/me4000.c | 29 +++++++++++++----------------
  1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/staging/comedi/drivers/me4000.c 
b/drivers/staging/comedi/drivers/me4000.c
index 3d12e91..b7284d0 100644
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -1505,6 +1505,13 @@ static int me4000_auto_attach(struct comedi_device *dev,

        me4000_reset(dev);

+       if (pcidev->irq > 0) {
+               result = request_irq(pcidev->irq, me4000_ai_isr, IRQF_SHARED,
+                                 dev->board_name, dev);
+               if (result == 0)
+                       dev->irq = pcidev->irq;
+       }
+
        result = comedi_alloc_subdevices(dev, 4);

This will cause a NULL pointer dereference on the following line in me4000_ai_isr():

        struct comedi_subdevice *s = &dev->subdevices[0];

However, the bug gets fixed by your PATCH 20/51. (The later `if (!dev->attached) return IRQ_NONE;` in the interrupt handler ensures it does no further harm.)

        if (result)
                return result;
@@ -1525,22 +1532,12 @@ static int me4000_auto_attach(struct comedi_device *dev,
                s->range_table = &me4000_ai_range;
                s->insn_read = me4000_ai_insn_read;

-               if (pcidev->irq > 0) {
-                       if (request_irq(pcidev->irq, me4000_ai_isr,
-                                       IRQF_SHARED, dev->board_name, dev)) {
-                               dev_warn(dev->class_dev,
-                                       "request_irq failed\n");
-                       } else {
-                               dev->read_subdev = s;
-                               s->subdev_flags |= SDF_CMD_READ;
-                               s->cancel = me4000_ai_cancel;
-                               s->do_cmdtest = me4000_ai_do_cmd_test;
-                               s->do_cmd = me4000_ai_do_cmd;
-
-                               dev->irq = pcidev->irq;
-                       }
-               } else {
-                       dev_warn(dev->class_dev, "No interrupt available\n");
+               if (dev->irq) {
+                       dev->read_subdev = s;
+                       s->subdev_flags |= SDF_CMD_READ;
+                       s->cancel = me4000_ai_cancel;
+                       s->do_cmdtest = me4000_ai_do_cmd_test;
+                       s->do_cmd = me4000_ai_do_cmd;
                }
        } else {
                s->type = COMEDI_SUBD_UNUSED;



--
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbo...@mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-
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