PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken
Per PCIe r3.1, sec 2.2.6.2 and 7.8.4, a Requester may not use 8-bit Tags
unless its Extended Tag Field Enable is set, but all Receivers/Completers
must handle 8-bit Tags correctly regardless of their Extended Tag Field
Enable.
Some devices do not handle 8-bit Tags as Completers, so add a quirk for
them. If we find such a device, we disable Extended Tags for the entire
hierarchy to make peer-to-peer DMA possible.
The Broadcom HT2100 seems to have issues with handling 8-bit tags. Mark it
as broken.
The pci_walk_bus() in the quirk handles devices we've enumerated in the
past, and pci_configure_device() handles devices we enumerate in the
future.
Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1467674
Reported-and-tested-by: Wim ten Have <wim.ten.have@oracle.com>
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
[bhelgaas: changelog, tweak messages, rename bit and quirk]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>diff --git a/include/linux/pci.h b/include/linux/pci.h
index 4869e66..3b968d4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -451,6 +451,7 @@ struct pci_host_bridge {
void *release_data;
struct msi_controller *msi;
unsigned int ignore_reset_delay:1; /* for entire hierarchy */
+ unsigned int no_ext_tags:1; /* no Extended Tags */
/* Resource alignment requirements */
resource_size_t (*align_resource)(struct pci_dev *dev,
const struct resource *res,