Revert "PCI: update bridge resources to get more big ranges in PCI assign unssigned"
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 13 May 2010 01:39:45 +0000 (18:39 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 13 May 2010 01:39:45 +0000 (18:39 -0700)
This reverts commit 977d17bb1749517b353874ccdc9b85abc7a58c2a, because it
can cause problems with some devices not getting any resources at all
when the resource tree is re-allocated.

For an example of this, see

https://bugzilla.kernel.org/show_bug.cgi?id=15960
(originally https://bugtrack.alsa-project.org/alsa-bug/view.php?id=4982)
(lkml thread: http://lkml.org/lkml/2010/4/19/20)

where Peter Henriksson reported his Xonar DX sound card gone, because
the IO port region was no longer allocated.

Reported-bisected-and-tested-by: Peter Henriksson <peter.henriksson@gmail.com>
Requested-by: Andrew Morton <akpm@linux-foundation.org>
Requested-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/pci/setup-bus.c

index 4fe36d2e104930cc99cc7014b27614277d75c9f8..19b111383f62fe63c9859dfd509de2cda3801d9e 100644 (file)
@@ -838,65 +838,11 @@ static void pci_bus_dump_resources(struct pci_bus *bus)
        }
 }
 
-static int __init pci_bus_get_depth(struct pci_bus *bus)
-{
-       int depth = 0;
-       struct pci_dev *dev;
-
-       list_for_each_entry(dev, &bus->devices, bus_list) {
-               int ret;
-               struct pci_bus *b = dev->subordinate;
-               if (!b)
-                       continue;
-
-               ret = pci_bus_get_depth(b);
-               if (ret + 1 > depth)
-                       depth = ret + 1;
-       }
-
-       return depth;
-}
-static int __init pci_get_max_depth(void)
-{
-       int depth = 0;
-       struct pci_bus *bus;
-
-       list_for_each_entry(bus, &pci_root_buses, node) {
-               int ret;
-
-               ret = pci_bus_get_depth(bus);
-               if (ret > depth)
-                       depth = ret;
-       }
-
-       return depth;
-}
-
-/*
- * first try will not touch pci bridge res
- * second  and later try will clear small leaf bridge res
- * will stop till to the max  deepth if can not find good one
- */
 void __init
 pci_assign_unassigned_resources(void)
 {
        struct pci_bus *bus;
-       int tried_times = 0;
-       enum release_type rel_type = leaf_only;
-       struct resource_list_x head, *list;
-       unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
-                                 IORESOURCE_PREFETCH;
-       unsigned long failed_type;
-       int max_depth = pci_get_max_depth();
-       int pci_try_num;
 
-       head.next = NULL;
-
-       pci_try_num = max_depth + 1;
-       printk(KERN_DEBUG "PCI: max bus depth: %d pci_try_num: %d\n",
-                max_depth, pci_try_num);
-
-again:
        /* Depth first, calculate sizes and alignments of all
           subordinate buses. */
        list_for_each_entry(bus, &pci_root_buses, node) {
@@ -904,65 +850,9 @@ again:
        }
        /* Depth last, allocate resources and update the hardware. */
        list_for_each_entry(bus, &pci_root_buses, node) {
-               __pci_bus_assign_resources(bus, &head);
-       }
-       tried_times++;
-
-       /* any device complain? */
-       if (!head.next)
-               goto enable_and_dump;
-       failed_type = 0;
-       for (list = head.next; list;) {
-               failed_type |= list->flags;
-               list = list->next;
-       }
-       /*
-        * io port are tight, don't try extra
-        * or if reach the limit, don't want to try more
-        */
-       failed_type &= type_mask;
-       if ((failed_type == IORESOURCE_IO) || (tried_times >= pci_try_num)) {
-               free_failed_list(&head);
-               goto enable_and_dump;
-       }
-
-       printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
-                        tried_times + 1);
-
-       /* third times and later will not check if it is leaf */
-       if ((tried_times + 1) > 2)
-               rel_type = whole_subtree;
-
-       /*
-        * Try to release leaf bridge's resources that doesn't fit resource of
-        * child device under that bridge
-        */
-       for (list = head.next; list;) {
-               bus = list->dev->bus;
-               pci_bus_release_bridge_resources(bus, list->flags & type_mask,
-                                                 rel_type);
-               list = list->next;
-       }
-       /* restore size and flags */
-       for (list = head.next; list;) {
-               struct resource *res = list->res;
-
-               res->start = list->start;
-               res->end = list->end;
-               res->flags = list->flags;
-               if (list->dev->subordinate)
-                       res->flags = 0;
-
-               list = list->next;
-       }
-       free_failed_list(&head);
-
-       goto again;
-
-enable_and_dump:
-       /* Depth last, update the hardware. */
-       list_for_each_entry(bus, &pci_root_buses, node)
+               pci_bus_assign_resources(bus);
                pci_enable_bridges(bus);
+       }
 
        /* dump the resource on buses */
        list_for_each_entry(bus, &pci_root_buses, node) {