PCI: Mark Atheros AR93xx to avoid bus reset

commit c3e59ee4e76686b0c84ca8faa1011d10cd4ca1b8 upstream.

Reports against the TL-WDN4800 card indicate that PCI bus reset of this
Atheros device cause system lock-ups and resets.  I've also been able to
confirm this behavior on multiple systems.  The device never returns from
reset and attempts to access config space of the device after reset result
in hangs.  Blacklist bus reset for the device to avoid this issue.

[bhelgaas: This regression appeared in v3.14.  Andreas bisected it to
425c1b22 ("PCI: Add Virtual Channel to save/restore support"), but we
don't understand the mechanism by which that commit affects the reset
path.]

[bhelgaas: changelog, references]
Link: http://lkml.kernel.org/r/20140923210318.498dacbd@dualc.maya.org


Reported-by: Andreas Hartmann <andihartmann@freenet.de>
Tested-by: Andreas Hartmann <andihartmann@freenet.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>