Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937390Ab3DJWrq (ORCPT ); Wed, 10 Apr 2013 18:47:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56239 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937338Ab3DJWri (ORCPT ); Wed, 10 Apr 2013 18:47:38 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bjorn Helgaas , "Rafael J. Wysocki" , Yinghai Lu Subject: [ 51/64] Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus" Date: Wed, 10 Apr 2013 15:46:48 -0700 Message-Id: <20130410224345.244195942@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130410224333.114387235@linuxfoundation.org> References: <20130410224333.114387235@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6636 Lines: 206 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bjorn Helgaas commit b8178f130e25c1bdac1c33e0996f1ff6e20ec08e upstream. This reverts commit 8c33f51df406e1a1f7fa4e9b244845b7ebd61fa6. 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 Acked-by: Rafael J. Wysocki Acked-by: Yinghai Lu Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/pci_root.c | 121 +++++++++++++++++++++++------------------------- 1 file changed, 59 insertions(+), 62 deletions(-) --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -454,7 +454,6 @@ static int acpi_pci_root_add(struct acpi acpi_handle handle; struct acpi_device *child; u32 flags, base_flags; - bool is_osc_granted = false; root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL); if (!root) @@ -525,60 +524,6 @@ static int acpi_pci_root_add(struct acpi flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT; acpi_pci_osc_support(root, flags); - /* Indicate support for various _OSC capabilities. */ - if (pci_ext_cfg_avail()) - flags |= OSC_EXT_PCI_CONFIG_SUPPORT; - if (pcie_aspm_support_enabled()) { - flags |= OSC_ACTIVE_STATE_PWR_SUPPORT | - OSC_CLOCK_PWR_CAPABILITY_SUPPORT; - } - if (pci_msi_enabled()) - flags |= OSC_MSI_SUPPORT; - if (flags != base_flags) { - status = acpi_pci_osc_support(root, flags); - if (ACPI_FAILURE(status)) { - dev_info(&device->dev, "ACPI _OSC support " - "notification failed, disabling PCIe ASPM\n"); - pcie_no_aspm(); - flags = base_flags; - } - } - if (!pcie_ports_disabled - && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) { - flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL - | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL - | OSC_PCI_EXPRESS_PME_CONTROL; - - if (pci_aer_available()) { - if (aer_acpi_firmware_first()) - dev_dbg(&device->dev, - "PCIe errors handled by BIOS.\n"); - else - flags |= OSC_PCI_EXPRESS_AER_CONTROL; - } - - dev_info(&device->dev, - "Requesting ACPI _OSC control (0x%02x)\n", flags); - - status = acpi_pci_osc_control_set(device->handle, &flags, - OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL); - if (ACPI_SUCCESS(status)) { - is_osc_granted = true; - dev_info(&device->dev, - "ACPI _OSC control (0x%02x) granted\n", flags); - } else { - is_osc_granted = false; - dev_info(&device->dev, - "ACPI _OSC request failed (%s), " - "returned control mask: 0x%02x\n", - acpi_format_exception(status), flags); - } - } else { - dev_info(&device->dev, - "Unable to request _OSC control " - "(_OSC support mask: 0x%02x)\n", flags); - } - /* * TBD: Need PCI interface for enumeration/configuration of roots. */ @@ -618,14 +563,66 @@ static int acpi_pci_root_add(struct acpi list_for_each_entry(child, &device->children, node) acpi_pci_bridge_scan(child); - /* ASPM setting */ - if (is_osc_granted) { - if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) - pcie_clear_aspm(root->bus); + /* Indicate support for various _OSC capabilities. */ + if (pci_ext_cfg_avail()) + flags |= OSC_EXT_PCI_CONFIG_SUPPORT; + if (pcie_aspm_support_enabled()) + flags |= OSC_ACTIVE_STATE_PWR_SUPPORT | + OSC_CLOCK_PWR_CAPABILITY_SUPPORT; + if (pci_msi_enabled()) + flags |= OSC_MSI_SUPPORT; + if (flags != base_flags) { + status = acpi_pci_osc_support(root, flags); + if (ACPI_FAILURE(status)) { + dev_info(root->bus->bridge, "ACPI _OSC support " + "notification failed, disabling PCIe ASPM\n"); + pcie_no_aspm(); + flags = base_flags; + } + } + + if (!pcie_ports_disabled + && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) { + flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL + | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL + | OSC_PCI_EXPRESS_PME_CONTROL; + + if (pci_aer_available()) { + if (aer_acpi_firmware_first()) + dev_dbg(root->bus->bridge, + "PCIe errors handled by BIOS.\n"); + else + flags |= OSC_PCI_EXPRESS_AER_CONTROL; + } + + dev_info(root->bus->bridge, + "Requesting ACPI _OSC control (0x%02x)\n", flags); + + status = acpi_pci_osc_control_set(device->handle, &flags, + OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL); + if (ACPI_SUCCESS(status)) { + dev_info(root->bus->bridge, + "ACPI _OSC control (0x%02x) granted\n", flags); + if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { + /* + * We have ASPM control, but the FADT indicates + * that it's unsupported. Clear it. + */ + pcie_clear_aspm(root->bus); + } + } else { + dev_info(root->bus->bridge, + "ACPI _OSC request failed (%s), " + "returned control mask: 0x%02x\n", + acpi_format_exception(status), flags); + pr_info("ACPI _OSC control for PCIe not granted, " + "disabling ASPM\n"); + pcie_no_aspm(); + } } else { - pr_info("ACPI _OSC control for PCIe not granted, " - "disabling ASPM\n"); - pcie_no_aspm(); + dev_info(root->bus->bridge, + "Unable to request _OSC control " + "(_OSC support mask: 0x%02x)\n", flags); } pci_acpi_add_bus_pm_notifier(device, root->bus); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/