On 2013-12-05 20:43, H Hartley Sweeten wrote:
Do the request_irq() before setting up the subdevices. Only hook up
the command support of the irq was sucessfully requested.
Note that, because of the IRQF_SHARED flag, nidio_interrupt() _may_
be called before the device is ready and the subdevices are setup.
This condition is handled by the (!dev->attached) sanity check. The
initialzation of the local variable pointers before this test is
still safe since we are just getting addresses and not dereferencing
them.
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/ni_pcidio.c | 38 +++++++++++++++---------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_pcidio.c
b/drivers/staging/comedi/drivers/ni_pcidio.c
index 30c46a3..8ab8a87 100644
--- a/drivers/staging/comedi/drivers/ni_pcidio.c
+++ b/drivers/staging/comedi/drivers/ni_pcidio.c
@@ -1011,6 +1011,14 @@ static int nidio_auto_attach(struct comedi_device *dev,
nidio_reset_board(dev);
+ irq = mite_irq(devpriv->mite);
+ if (irq) {
+ ret = request_irq(irq, nidio_interrupt, IRQF_SHARED,
+ dev->board_name, dev);
+ if (ret == 0)
+ dev->irq = irq;
+ }
+
ret = comedi_alloc_subdevices(dev, 1);
Unfortunately, the interrupt handler `nidio_interrupt()` still
dereferences the subdevice pointer before it tests `dev->attached`:
struct comedi_subdevice *s = dev->read_subdev;
struct comedi_async *async = s->async;
/* ... */
if (!dev->attached) {
return IRQ_NONE;
}
so this can still fail if `dev->read_subdev` hasn't been set yet.
if (ret)
return ret;
@@ -1019,31 +1027,23 @@ static int nidio_auto_attach(struct comedi_device *dev,
readb(devpriv->mite->daq_io_addr + Chip_Version));
s = &dev->subdevices[0];
-
- dev->read_subdev = s;
s->type = COMEDI_SUBD_DIO;
- s->subdev_flags =
- SDF_READABLE | SDF_WRITABLE | SDF_LSAMPL | SDF_PACKED |
- SDF_CMD_READ;
+ s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_LSAMPL | SDF_PACKED;
s->n_chan = 32;
s->range_table = &range_digital;
s->maxdata = 1;
s->insn_config = &ni_pcidio_insn_config;
s->insn_bits = &ni_pcidio_insn_bits;
- s->do_cmd = &ni_pcidio_cmd;
- s->do_cmdtest = &ni_pcidio_cmdtest;
- s->cancel = &ni_pcidio_cancel;
- s->len_chanlist = 32; /* XXX */
- s->buf_change = &ni_pcidio_change;
- s->async_dma_dir = DMA_BIDIRECTIONAL;
- s->poll = &ni_pcidio_poll;
-
- irq = mite_irq(devpriv->mite);
- if (irq) {
- ret = request_irq(irq, nidio_interrupt, IRQF_SHARED,
- dev->board_name, dev);
- if (ret == 0)
- dev->irq = irq;
+ if (dev->irq) {
+ dev->read_subdev = s;
+ s->subdev_flags |= SDF_CMD_READ;
+ s->async_dma_dir = DMA_BIDIRECTIONAL;
+ s->len_chanlist = s->n_chan;
+ s->do_cmd = ni_pcidio_cmd;
+ s->do_cmdtest = ni_pcidio_cmdtest;
+ s->cancel = ni_pcidio_cancel;
+ s->poll = ni_pcidio_poll;
+ s->buf_change = ni_pcidio_change;
}
return 0;
--
-=( 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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