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| author | Bjorn Helgaas <bhelgaas@google.com> | 2012-04-30 15:21:02 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2012-04-30 15:21:02 -0600 |
| commit | 284f5f9dbac170b054c1e386ef92cbf654e91bba (patch) | |
| tree | 74cacc94070d5590378c368fa7378d37319d07be /Documentation/kernel-parameters.txt | |
| parent | 66f75a5d028beaf67c931435fdc3e7823125730c (diff) | |
| download | lwn-284f5f9dbac170b054c1e386ef92cbf654e91bba.tar.gz lwn-284f5f9dbac170b054c1e386ef92cbf654e91bba.zip | |
PCI: work around Stratus ftServer broken PCIe hierarchy
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:
[0000:02]-+-00.0-[03-3c]--+-00.0-[04-09]--...
\-01.0-[0a-0d]--+-[USB]
+-[NIC]
+-...
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: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1601e5a8b71..f995195409fd 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2161,6 +2161,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. on: Turn realloc on realloc same as realloc=on noari do not use PCIe ARI. + pcie_scan_all Scan all possible PCIe devices. Otherwise we + only look for one device below a PCIe downstream + port. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. |