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PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken

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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: 60db3a4d8c ("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>
This commit is contained in:
Sinan Kaya
2017-07-12 00:04:14 -04:00
committed by Bjorn Helgaas
parent 16f73eb02d
commit 62ce94a7a5
4 changed files with 54 additions and 7 deletions
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16
drivers/pci/quirks.c
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@@ -4681,3 +4681,19 @@ static void quirk_intel_no_flr(struct pci_dev *dev)
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr);
static void quirk_no_ext_tags(struct pci_dev *pdev)
{
struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
if (!bridge)
return;
bridge->no_ext_tags = 1;
dev_info(&pdev->dev, "disabling Extended Tags (this device can't handle them)\n");
pci_walk_bus(bridge->bus, pci_configure_extended_tags, NULL);
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0140, quirk_no_ext_tags);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0142, quirk_no_ext_tags);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0144, quirk_no_ext_tags);