...
Hmm. This makes the code look totally nonsensical.
It seems to come from the fact that we had a very odd way to check bogus
resources (namely "start == end"), but your code makes it _really_ hard to
see what is going on.
In fact, I think the old code was buggy too, because we actually *do* have
single-byte resources where start == end, as showb by google:
PCI: Ignore bogus resource 1 [3f6:3f6] of Symphony Labs SL82c105
PCI: Ignore bogus resource 3 [376:376] of Symphony Labs SL82c105
where that resource actually looks valid, and should have a single byte
alignment! Admittedly I think it was created with a quirk (can you get
that kind of resource from actually _probing_ a PCI device?) but I do
think that a single-byte resource is valid.
So I wonder if we shouldn't just make this a bit more readable and also a
bit more explicit with something like the appended..
NOTE! This will also consider a bridge resource at 0 to be an invalid
resource (since now the alignment will be zero), which is a bit odd and
makes me worry a bit. I wouldn't be surprised if some non-PC architectures
have PCI bridges at zero. But maybe they should be (or already are?)
marked IORESOURCE_PCI_FIXED?
Ben - the obvious "odd PCI bus resources" architecture would be POWER. Any
commentary?
Linus
---
drivers/pci/setup-res.c | 21 +++++++++++++++++----
1 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 4be7ccf..048ed77 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -211,6 +211,20 @@ int pci_assign_resource_fixed(struct pci_dev *dev, int resno)
EXPORT_SYMBOL_GPL(pci_assign_resource_fixed);
#endif
+static inline resource_size_t get_resource_alignment(int resno, struct resource *r)
+{
+ resource_size_t start = r->start, end = r->end;
+ resource_size_t alignment = 0;
+
+ /* End == start == 0 - invalid resource */
+ if (end && start <= end) {
+ alignment = end - start - 1;
+ if (resno >= PCI_BRIDGE_RESOURCES)
+ alignment = start;
+ }
+ return alignment;
+}
+
/* Sort resources by alignment */
void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
{
@@ -226,10 +240,10 @@ void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
if (r->flags & IORESOURCE_PCI_FIXED)
continue;
- r_align = r->end - r->start;
-
- if (!(r->flags) || r->parent)
+ if (!r->flags || r->parent)
continue;
+
+ r_align = get_resource_alignment(i, r);
if (!r_align) {
printk(KERN_WARNING "PCI: Ignore bogus resource %d "
"[%llx:%llx] of %s\n",
@@ -237,7 +251,6 @@ void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
(unsigned long long)r->end, pci_name(dev));
continue;
}
- r_align = (i < PCI_BRIDGE_RESOURCES) ? r_align + 1 : r->start;
for (list = head; ; list = list->next) {
resource_size_t align = 0;
struct resource_list *ln = list->next;
--
