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>

drivers/pci/probe.c

@@ -22,6 +22,18 @@ EXPORT_SYMBOL(pci_root_buses);
 
 LIST_HEAD(pci_devices);
 
+/*
+ * Some device drivers need know if pci is initiated.
+ * Basically, we think pci is not initiated when there
+ * is no device in list of pci_devices.
+ */
+int no_pci_devices(void)
+{
+	return list_empty(&pci_devices);
+}
+
+EXPORT_SYMBOL(no_pci_devices);
+
 #ifdef HAVE_PCI_LEGACY
 /**
  * pci_create_legacy_files - create legacy I/O port and memory files

include/asm-i386/ide.h

@@ -40,14 +40,13 @@ static __inline__ int ide_default_irq(unsigned long base)
 
 static __inline__ unsigned long ide_default_io_base(int index)
 {
-	struct pci_dev *pdev;
 	/*
 	 *	If PCI is present then it is not safe to poke around
 	 *	the other legacy IDE ports. Only 0x1f0 and 0x170 are
 	 *	defined compatibility mode ports for PCI. A user can 
 	 *	override this using ide= but we must default safe.
 	 */
-	if ((pdev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL)) == NULL) {
+	if (no_pci_devices()) {
 		switch(index) {
 			case 2: return 0x1e8;
 			case 3: return 0x168;
@@ -55,7 +54,6 @@ static __inline__ unsigned long ide_default_io_base(int index)
 			case 5: return 0x160;
 		}
 	}
-	pci_dev_put(pdev);
 	switch (index) {
 		case 0:	return 0x1f0;
 		case 1:	return 0x170;

include/linux/pci.h

@@ -432,6 +432,8 @@ extern struct bus_type pci_bus_type;
  * 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 @@ static inline struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *
 { 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)