diff options
author | Sinan Kaya <okaya@codeaurora.org> | 2017-07-12 00:04:14 -0400 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-07-31 14:31:22 -0500 |
commit | 62ce94a7a5a54aac80975f5e6731707225d4077e (patch) | |
tree | af6e5d8fb778bb2fe51a14dcde3b0355b1035bf5 /drivers/pci/probe.c | |
parent | 16f73eb02d7e1765ccab3d2018e0bd98eb93d973 (diff) | |
download | linux-62ce94a7a5a54aac80975f5e6731707225d4077e.tar.bz2 |
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>
Diffstat (limited to 'drivers/pci/probe.c')
-rw-r--r-- | drivers/pci/probe.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c31310db0404..c81c9835f4c7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1745,21 +1745,50 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp) */ } -static void pci_configure_extended_tags(struct pci_dev *dev) +int pci_configure_extended_tags(struct pci_dev *dev, void *ign) { - u32 dev_cap; + struct pci_host_bridge *host; + u32 cap; + u16 ctl; int ret; if (!pci_is_pcie(dev)) - return; + return 0; - ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap); + ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); if (ret) - return; + return 0; + + if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) + return 0; - if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG) + ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); + if (ret) + return 0; + + host = pci_find_host_bridge(dev->bus); + if (!host) + return 0; + + /* + * If some device in the hierarchy doesn't handle Extended Tags + * correctly, make sure they're disabled. + */ + if (host->no_ext_tags) { + if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { + dev_info(&dev->dev, "disabling Extended Tags\n"); + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, + PCI_EXP_DEVCTL_EXT_TAG); + } + return 0; + } + + if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { + dev_info(&dev->dev, "enabling Extended Tags\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); + } + return 0; } static void pci_configure_device(struct pci_dev *dev) @@ -1768,7 +1797,7 @@ static void pci_configure_device(struct pci_dev *dev) int ret; pci_configure_mps(dev); - pci_configure_extended_tags(dev); + pci_configure_extended_tags(dev, NULL); memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); |