[PATCH] x86: pci_assign_unassigned_resources() update

I had some time to think about PCI assign issues in 2.6.13-rc series.

The major problem here is that we call pci_assign_unassigned_resources()
way too early - at subsys_initcall level. Therefore we give no chances
to ACPI and PnP routines (called at fs_initcall level) to reserve their
respective resources properly, as the comments in drivers/pnp/system.c
and drivers/acpi/motherboard.c suggest:

 /**
  * Reserve motherboard resources after PCI claim BARs,
  * but before PCI assign resources for uninitialized PCI devices
  */

So I moved the pci_assign_unassigned_resources() call to
pcibios_assign_resources() (fs_initcall), which should hopefully fix a
lot of problems and make PCIBIOS_MIN_IO tweaks unnecessary.

Other changes:
- remove resource assignment code from pcibios_assign_resources(), since
  it duplicates pci_assign_unassigned_resources() functionality and
  actually does nothing in 2.6.13;
- modify ROM assignment code as per Ben's suggestion: try to use firmware
  settings by default (if PCI_ASSIGN_ROMS is not set);
- set CARDBUS_IO_SIZE back to 4K as it's a wonderful stress test for
  various setups.

Confirmed by Tero Roponen <teanropo@cc.jyu.fi> (who had problems with
the 4kB CardBus IO size previously).

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 16 insertions, 34 deletions

diff --git a/arch/i386/pci/common.c b/arch/i386/pci/common.c
index ade5bc57c34c..c96bea14b98f 100644
--- a/arch/i386/pci/common.c
+++ b/arch/i386/pci/common.c
@@ -165,7 +165,6 @@ static int __init pcibios_init(void)
         if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
                 pcibios_sort();
 #endif
-        pci_assign_unassigned_resources();
         return 0;
 }
 
diff --git a/arch/i386/pci/i386.c b/arch/i386/pci/i386.c
index 93a364c82150..3cc480998a47 100644
--- a/arch/i386/pci/i386.c
+++ b/arch/i386/pci/i386.c
@@ -170,43 +170,26 @@ static void __init pcibios_allocate_resources(int pass)
 static int __init pcibios_assign_resources(void)
 {
         struct pci_dev *dev = NULL;
-        int idx;
-        struct resource *r;
-
-        for_each_pci_dev(dev) {
-                int class = dev->class >> 8;
-
-                /* Don't touch classless devices and host bridges */
-                if (!class || class == PCI_CLASS_BRIDGE_HOST)
-                        continue;
-
-                for(idx=0; idx<6; idx++) {
-                        r = &dev->resource[idx];
-
-                        /*
-                         *  Don't touch IDE controllers and I/O ports of video cards!
-                         */
-                        if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) ||
-                            (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO)))
-                                continue;
-
-                        /*
-                         *  We shall assign a new address to this resource, either because
-                         *  the BIOS forgot to do so or because we have decided the old
-                         *  address was unusable for some reason.
-                         */
-                        if (!r->start && r->end)
-                                pci_assign_resource(dev, idx);
-                }
+        struct resource *r, *pr;
 
-                if (pci_probe & PCI_ASSIGN_ROMS) {
+        if (!(pci_probe & PCI_ASSIGN_ROMS)) {
+                /* Try to use BIOS settings for ROMs, otherwise let
+                   pci_assign_unassigned_resources() allocate the new
+                   addresses. */
+                for_each_pci_dev(dev) {
                         r = &dev->resource[PCI_ROM_RESOURCE];
-                        r->end -= r->start;
-                        r->start = 0;
-                        if (r->end)
-                                pci_assign_resource(dev, PCI_ROM_RESOURCE);
+                        if (!r->flags || !r->start)
+                                continue;
+                        pr = pci_find_parent_resource(dev, r);
+                        if (!pr || request_resource(pr, r) < 0) {
+                                r->end -= r->start;
+                                r->start = 0;
+                        }
                 }
         }
+
+        pci_assign_unassigned_resources();
+
         return 0;
 }