diff options
Diffstat (limited to 'drivers/pci/probe.c')
| -rw-r--r-- | drivers/pci/probe.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index cd7b6de9376c..fe5b50bd7536 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -170,7 +170,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, { u32 l, sz, mask; u16 orig_cmd; - struct pci_bus_region region; + struct pci_bus_region region, inverted_region; bool bar_too_big = false, bar_disabled = false; mask = type ? PCI_ROM_ADDRESS_MASK : ~0; @@ -266,6 +266,26 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, } pcibios_bus_to_resource(dev, res, ®ion); + pcibios_resource_to_bus(dev, &inverted_region, res); + + /* + * If "A" is a BAR value (a bus address), "bus_to_resource(A)" is + * the corresponding resource address (the physical address used by + * the CPU. Converting that resource address back to a bus address + * should yield the original BAR value: + * + * resource_to_bus(bus_to_resource(A)) == A + * + * If it doesn't, CPU accesses to "bus_to_resource(A)" will not + * be claimed by the device. + */ + if (inverted_region.start != region.start) { + dev_info(&dev->dev, "reg 0x%x: initial BAR value %pa invalid; forcing reassignment\n", + pos, ®ion.start); + res->flags |= IORESOURCE_UNSET; + res->end -= res->start; + res->start = 0; + } goto out; |