Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus"
This reverts commit8c33f51df4
. Conflicts: drivers/acpi/pci_root.c This commit broke some pre-1.1 PCIe devices by leaving them with ASPM enabled. Previously, we had disabled ASPM on these devices because many of them don't implement it correctly (per149e1637
). Requesting _OSC control early means that aspm_disabled may be set before we scan the PCI bus and configure link ASPM state. But the ASPM configuration currently skips the check for pre-PCIe 1.1 devices when aspm_disabled is set, like this: acpi_pci_root_add acpi_pci_osc_support if (flags != base_flags) pcie_no_aspm aspm_disabled = 1 pci_acpi_scan_root ... pcie_aspm_init_link_state pcie_aspm_sanity_check if (!aspm_disabled) /* check for pre-PCIe 1.1 device */ Therefore, setting aspm_disabled early means that we leave ASPM enabled on these pre-PCIe 1.1 devices, which is a regression for some devices. The best fix would be to clean up the ASPM init so we can evaluate _OSC before scanning the bug (that way boot-time and hot-add discovery will work the same), but that requires significant rework. For now, we'll just revert the _OSC change as the lowest-risk fix. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=55211 Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> CC: stable@vger.kernel.org # v3.8+
This commit is contained in:
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commit
b8178f130e
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@ -415,7 +415,6 @@ static int acpi_pci_root_add(struct acpi_device *device,
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struct acpi_pci_root *root;
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struct acpi_pci_driver *driver;
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u32 flags, base_flags;
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bool is_osc_granted = false;
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root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
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if (!root)
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@ -476,6 +475,30 @@ static int acpi_pci_root_add(struct acpi_device *device,
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flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
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acpi_pci_osc_support(root, flags);
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/*
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* TBD: Need PCI interface for enumeration/configuration of roots.
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*/
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mutex_lock(&acpi_pci_root_lock);
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list_add_tail(&root->node, &acpi_pci_roots);
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mutex_unlock(&acpi_pci_root_lock);
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/*
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* Scan the Root Bridge
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* --------------------
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* Must do this prior to any attempt to bind the root device, as the
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* PCI namespace does not get created until this call is made (and
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* thus the root bridge's pci_dev does not exist).
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*/
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root->bus = pci_acpi_scan_root(root);
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if (!root->bus) {
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printk(KERN_ERR PREFIX
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"Bus %04x:%02x not present in PCI namespace\n",
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root->segment, (unsigned int)root->secondary.start);
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result = -ENODEV;
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goto out_del_root;
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}
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/* Indicate support for various _OSC capabilities. */
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if (pci_ext_cfg_avail())
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flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
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@ -494,6 +517,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
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flags = base_flags;
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}
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}
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if (!pcie_ports_disabled
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&& (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
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flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
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@ -514,54 +538,28 @@ static int acpi_pci_root_add(struct acpi_device *device,
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status = acpi_pci_osc_control_set(device->handle, &flags,
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OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
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if (ACPI_SUCCESS(status)) {
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is_osc_granted = true;
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dev_info(&device->dev,
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"ACPI _OSC control (0x%02x) granted\n", flags);
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if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
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/*
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* We have ASPM control, but the FADT indicates
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* that it's unsupported. Clear it.
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*/
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pcie_clear_aspm(root->bus);
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}
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} else {
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is_osc_granted = false;
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dev_info(&device->dev,
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"ACPI _OSC request failed (%s), "
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"returned control mask: 0x%02x\n",
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acpi_format_exception(status), flags);
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pr_info("ACPI _OSC control for PCIe not granted, "
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"disabling ASPM\n");
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pcie_no_aspm();
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}
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} else {
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dev_info(&device->dev,
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"Unable to request _OSC control "
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"(_OSC support mask: 0x%02x)\n", flags);
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}
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/*
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* TBD: Need PCI interface for enumeration/configuration of roots.
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*/
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mutex_lock(&acpi_pci_root_lock);
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list_add_tail(&root->node, &acpi_pci_roots);
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mutex_unlock(&acpi_pci_root_lock);
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/*
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* Scan the Root Bridge
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* --------------------
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* Must do this prior to any attempt to bind the root device, as the
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* PCI namespace does not get created until this call is made (and
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* thus the root bridge's pci_dev does not exist).
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*/
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root->bus = pci_acpi_scan_root(root);
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if (!root->bus) {
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printk(KERN_ERR PREFIX
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"Bus %04x:%02x not present in PCI namespace\n",
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root->segment, (unsigned int)root->secondary.start);
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result = -ENODEV;
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goto out_del_root;
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}
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/* ASPM setting */
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if (is_osc_granted) {
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if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM)
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pcie_clear_aspm(root->bus);
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} else {
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pr_info("ACPI _OSC control for PCIe not granted, "
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"disabling ASPM\n");
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pcie_no_aspm();
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"Unable to request _OSC control "
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"(_OSC support mask: 0x%02x)\n", flags);
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}
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pci_acpi_add_bus_pm_notifier(device, root->bus);
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