Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus"
This reverts commit 8c33f51d. 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 (per 149e1637 ). 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+
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be7f088b
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