tree 0ea927e4a1acb8f5a11c29642b960309c732c3a9
parent 8605c6844fb9bdf55471bb87c3ac62d44eb34e04
author Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 1325705036 -0500
committer Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 1326387607 -0500

pci: Introduce __pci_reset_function_locked to be used when holding device_lock.

The use case of this is when a driver wants to call FLR when a device
is attached to it using the SysFS "bind" or "unbind" functionality.

The call chain when a user does "bind" looks as so:

 echo "0000:01.07.0" > /sys/bus/pci/drivers/XXXX/bind

and ends up calling:
  driver_bind:
    device_lock(dev);  <=== TAKES LOCK
    XXXX_probe:
         .. pci_enable_device()
         ...__pci_reset_function(), which calls
                 pci_dev_reset(dev, 0):
                        if (!0) {
                                device_lock(dev) <==== DEADLOCK

The __pci_reset_function_locked function allows the the drivers
'probe' function to call the "pci_reset_function" while still holding
the driver mutex lock.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>