PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies

In a struct pcie_link_state, link->root points to the pcie_link_state of
the root of the PCIe hierarchy.  For the topmost link, this points to
itself (link->root = link).  For others, we copy the pointer from the
parent (link->root = link->parent->root).

Previously we recognized that Root Ports originated PCIe hierarchies, but
we treated PCI/PCI-X to PCIe Bridges as being in the middle of the
hierarchy, and when we tried to copy the pointer from link->parent->root,
there was no parent, and we dereferenced a NULL pointer:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
  IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820

Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just
like Root Ports do, so link->root for these devices should also point to
itself.

Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181
Tested-by: lists@ssl-mail.com
Tested-by: Jayachandran C. <jnair@caviumnetworks.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v4.2+

path: root/include/dt-bindings/leds/leds-pca9532.h

/*
 * This header provides constants for pca9532 LED bindings.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#ifndef _DT_BINDINGS_LEDS_PCA9532_H
#define _DT_BINDINGS_LEDS_PCA9532_H

#define PCA9532_TYPE_NONE         0
#define PCA9532_TYPE_LED          1
#define PCA9532_TYPE_N2100_BEEP   2
#define PCA9532_TYPE_GPIO         3
#define PCA9532_LED_TIMER2        4

#endif /* _DT_BINDINGS_LEDS_PCA9532_H */