[ 063/262] staging: comedi: amplc_pci224: Fix PCI ref count

[Greg Kroah-Hartman]

From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ian Abbott <abbotti@xxxxxxxxx>

commit cadf84bfeb80e216fde328d357fe856160157d2c upstream.

When attaching a PCI device manually via the comedi driver `attach` hook
(`pci224_attach()`) (called by the comedi core for the
`COMEDI_DEVCONFIG` ioctl), its reference count is incremented in the
`for_each_pci_dev` loop (in `pci224_find_pci_dev()`).  It is decremented
when the `detach` hook (`pci224_detach()`) is called to detach the
device.  However, when the PCI device is attached automatically via the
`attach_pci` hook (`pci224_attach_pci()`, called at probe time via
`comedi_pci_auto_config()`) it's reference count is not incremented so
there will be an unmatched decrement when detaching the device.

Increment the PCI device reference count in `pci224_attach_pci()` to
correct the mismatch.

Once support for manual configuration has been removed from this driver,
the calls to `pci_dev_get()` and `pci_dev_put()` can be removed.

Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/staging/comedi/drivers/amplc_pci224.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/staging/comedi/drivers/amplc_pci224.c
+++ b/drivers/staging/comedi/drivers/amplc_pci224.c
@@ -1519,6 +1519,13 @@ pci224_attach_pci(struct comedi_device *
 		       dev->minor, DRIVER_NAME);
 		return -EINVAL;
 	}
+	/*
+	 * Need to 'get' the PCI device to match the 'put' in pci224_detach().
+	 * TODO: Remove the pci_dev_get() and matching pci_dev_put() once
+	 * support for manual attachment of PCI devices via pci224_attach()
+	 * has been removed.
+	 */
+	pci_dev_get(pci_dev);
 	return pci224_attach_common(dev, pci_dev, NULL);
 }
 


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