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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 /drivers/pci | |
| parent | 66f75a5d028beaf67c931435fdc3e7823125730c (diff) | |
| download | talos-obmc-linux-284f5f9dbac170b054c1e386ef92cbf654e91bba.tar.gz talos-obmc-linux-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 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 3 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 8 |
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 111569ccab43..8e6c38817036 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -22,6 +22,7 @@ #include <linux/interrupt.h> #include <linux/device.h> #include <linux/pm_runtime.h> +#include <asm-generic/pci-bridge.h> #include <asm/setup.h> #include "pci.h" @@ -3893,6 +3894,8 @@ static int __init pci_setup(char *str) pcie_bus_config = PCIE_BUS_PERFORMANCE; } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) { pcie_bus_config = PCIE_BUS_PEER2PEER; + } else if (!strncmp(str, "pcie_scan_all", 13)) { + pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); } else { printk(KERN_ERR "PCI: Unknown option `%s'\n", str); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 5e1ca3c58a7d..2dc8675eea1a 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/cpumask.h> #include <linux/pci-aspm.h> +#include <asm-generic/pci-bridge.h> #include "pci.h" #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ @@ -1395,10 +1396,13 @@ static unsigned no_next_fn(struct pci_dev *dev, unsigned fn) static int only_one_child(struct pci_bus *bus) { struct pci_dev *parent = bus->self; + if (!parent || !pci_is_pcie(parent)) return 0; - if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT || - parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM) + if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT) + return 1; + if (parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM && + !pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS)) return 1; return 0; } |
