• Bjorn Helgaas's avatar
    PCI: work around Stratus ftServer broken PCIe hierarchy · 284f5f9d
    Bjorn Helgaas authored
    A PCIe downstream port is a P2P bridge.  Its secondary interface is
    a link that should lead only to device 0 (unless ARI is enabled)[1], so
    we don't probe for non-zero device numbers.
    Some Stratus ftServer systems have a PCIe downstream port (02:00.0) that
    leads to both an upstream port (03:00.0) and a downstream port (03:01.0),
    and 03:01.0 has important devices below it:
    Previously, we didn't enumerate device 03:01.0, so USB and the network
    didn't work.  This patch adds a DMI quirk to scan all device numbers,
    not just 0, below a downstream port.
    Based on a patch by Prarit Bhargava.
    [1] PCIe spec r3.0, sec 7.3.1
    CC: Myron Stowe <mstowe@redhat.com>
    CC: Don Dutile <ddutile@redhat.com>
    CC: James Paradis <james.paradis@stratus.com>
    CC: Matthew Wilcox <matthew.r.wilcox@intel.com>
    CC: Jesse Barnes <jbarnes@virtuousgeek.org>
    CC: Prarit Bhargava <prarit@redhat.com>
    Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
pci-bridge.h 1.69 KB