ide: legacy PCI bus order probing fixes

IDE PCI host drivers should register themselves with IDE core only when
IDE driver is built-in, otherwise (IDE driver is modular and thus IDE PCI
host drivers are also modular) the code has no effect and just complicates
the probing.

Fix it by adding new config option CONFIG_IDEPCI_PCIBUS (defined only when
needed and invisible to the user) and covering by #ifdef/#endif the code
in question.  It turned out that "ide=reverse" was silently accepted but did
nothing in case when IDE driver was modular, this is fixed now.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/Kconfig

@@ -371,6 +371,9 @@ config IDEPCI_SHARE_IRQ
 	  It is safe to say Y to this question, in most cases.
 	  If unsure, say N.
 
+config IDEPCI_PCIBUS_ORDER
+	def_bool PCI && BLK_DEV_IDE=y && BLK_DEV_IDEPCI
+
 config BLK_DEV_OFFBOARD
 	bool "Boot off-board chipsets first support"
 	depends on PCI && BLK_DEV_IDEPCI

drivers/ide/ide.c

@@ -172,7 +172,7 @@ static int system_bus_speed;	/* holds what we think is VESA/PCI bus speed */
 DECLARE_MUTEX(ide_cfg_sem);
  __cacheline_aligned_in_smp DEFINE_SPINLOCK(ide_lock);
 
-#ifdef CONFIG_BLK_DEV_IDEPCI
+#ifdef CONFIG_IDEPCI_PCIBUS_ORDER
 static int ide_scan_direction; /* THIS was formerly 2.2.x pci=reverse */
 #endif
 
@@ -1333,13 +1333,13 @@ static int __init ide_setup(char *s)
 		return 1;
 	}
 
-#ifdef CONFIG_BLK_DEV_IDEPCI
+#ifdef CONFIG_IDEPCI_PCIBUS_ORDER
 	if (!strcmp(s, "ide=reverse")) {
 		ide_scan_direction = 1;
 		printk(" : Enabled support for IDE inverse scan order.\n");
 		return 1;
 	}
-#endif /* CONFIG_BLK_DEV_IDEPCI */
+#endif
 
 #ifdef CONFIG_BLK_DEV_IDEACPI
 	if (!strcmp(s, "ide=noacpi")) {
@@ -1599,9 +1599,9 @@ extern void __init h8300_ide_init(void);
  */
 static void __init probe_for_hwifs (void)
 {
-#ifdef CONFIG_BLK_DEV_IDEPCI
+#ifdef CONFIG_IDEPCI_PCIBUS_ORDER
 	ide_scan_pcibus(ide_scan_direction);
-#endif /* CONFIG_BLK_DEV_IDEPCI */
+#endif
 
 #ifdef CONFIG_ETRAX_IDE
 	{

drivers/ide/setup-pci.c

@@ -772,6 +772,7 @@ int ide_setup_pci_devices(struct pci_dev *dev1, struct pci_dev *dev2,
 
 EXPORT_SYMBOL_GPL(ide_setup_pci_devices);
 
+#ifdef CONFIG_IDEPCI_PCIBUS_ORDER
 /*
  *	Module interfaces
  */
@@ -878,3 +879,4 @@ void __init ide_scan_pcibus (int scan_direction)
 		__pci_register_driver(d, d->driver.owner, d->driver.mod_name);
 	}
 }
+#endif

include/linux/ide.h

@@ -1205,9 +1205,14 @@ void ide_init_disk(struct gendisk *, ide_drive_t *);
 
 extern int ideprobe_init(void);
 
+#ifdef CONFIG_IDEPCI_PCIBUS_ORDER
 extern void ide_scan_pcibus(int scan_direction) __init;
 extern int __ide_pci_register_driver(struct pci_driver *driver, struct module *owner, const char *mod_name);
 #define ide_pci_register_driver(d) __ide_pci_register_driver(d, THIS_MODULE, KBUILD_MODNAME)
+#else
+#define ide_pci_register_driver(d) pci_register_driver(d)
+#endif
+
 void ide_pci_setup_ports(struct pci_dev *, struct ide_pci_device_s *, int, ata_index_t *);
 extern void ide_setup_pci_noise (struct pci_dev *dev, struct ide_pci_device_s *d);