[PATCH] yenta oops fix

In some cases, especially on modern laptops with a lot of PCI and
cardbus bridges, we're unable to assign correct secondary/subordinate
bus numbers to all cardbus bridges due to BIOS limitations unless
we are using "pci=assign-busses" boot option.
So some cardbus controllers may not have attached subordinate pci_bus
structure, and yenta driver must cope with it - just ignore such cardbus
bridges.

For example, see https://bugzilla.novell.com/show_bug.cgi?id=113778

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/pcmcia/yenta_socket.c b/drivers/pcmcia/yenta_socket.c
index f0997c36c9b7..2e43911b4876 100644
--- a/drivers/pcmcia/yenta_socket.c
+++ b/drivers/pcmcia/yenta_socket.c
@@ -1045,7 +1045,18 @@ static int __devinit yenta_probe (struct pci_dev *dev, const struct pci_device_i
 {
         struct yenta_socket *socket;
         int ret;
-        
+
+        /*
+         * If we failed to assign proper bus numbers for this cardbus
+         * controller during PCI probe, its subordinate pci_bus is NULL.
+         * Bail out if so.
+         */
+        if (!dev->subordinate) {
+                printk(KERN_ERROR "Yenta: no bus associated with %s!\n",
+                        pci_name(dev));
+                return -ENODEV;
+        }
+
         socket = kmalloc(sizeof(struct yenta_socket), GFP_KERNEL);
         if (!socket)
                 return -ENOMEM;