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Revert "PCI: update bridge resources to get more big ranges in PCI assign unssigned"

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This reverts commit 977d17bb17, 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>
This commit is contained in:
Linus Torvalds 2010-05-12 18:39:45 -07:00
parent 7ac512aa82
commit 769d9968e4
1 changed files with 2 additions and 112 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

114
drivers/pci/setup-bus.c
View 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) {