fix jvc cdrom drive lockup

Before calling init_hwif_default, ide_unregister gets lock ide_lock and
disables irq.  init_hwif_default calls ide_default_io_base which calls
pci_get_device and later pci_get_subsys tries to apply for semaphore
pci_bus_sem and goes to sleep.

Mostly, pci_get_device should be called when irq is turned on.

ide_default_io_base just needs find if list pci_devices is empty.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 37a7158..5e84f2e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -432,6 +432,8 @@
  * code, or pci core code. */
 extern struct list_head pci_root_buses;	/* list of all known PCI buses */
 extern struct list_head pci_devices;	/* list of all devices */
+/* Some device drivers need know if pci is initiated */
+extern int no_pci_devices(void);
 
 void pcibios_fixup_bus(struct pci_bus *);
 int __must_check pcibios_enable_device(struct pci_dev *, int mask);
@@ -724,6 +726,7 @@
 { return NULL; }
 
 #define pci_dev_present(ids)	(0)
+#define no_pci_devices()	(1)
 #define pci_find_present(ids)	(NULL)
 #define pci_dev_put(dev)	do { } while (0)