From: Rafael J. Wysocki Date: Mon, 30 Jul 2012 20:40:32 +0000 (+0200) Subject: ACPI / PCI: Do not try to acquire _OSC control if that is hopeless X-Git-Tag: next-20120803~44^2~2^2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2d9c86774756193edff2a2a9077264f666c626de;p=karo-tx-linux.git ACPI / PCI: Do not try to acquire _OSC control if that is hopeless If acpi_pci_osc_support() fails for the given flags, it doesn't make sense to call acpi_pci_osc_control_set() down the road for the same flags, because it will certainly fail too. Moreover, problem diagnostics is then harder, because it is not too easy to identify the reason of the _OSC failure in those cases. For this reason, check the status returned by acpi_pci_osc_support() for PCIe support flags and do not attempt to execute acpi_pci_osc_control_set() for those flags and print a message if it's "failure". For compatibility with the existing code, disable ASPM in that case too. Signed-off-by: Rafael J. Wysocki Signed-off-by: Len Brown --- diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 7aff6312ce7c..c86b39217400 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -571,8 +571,15 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device) OSC_CLOCK_PWR_CAPABILITY_SUPPORT; if (pci_msi_enabled()) flags |= OSC_MSI_SUPPORT; - if (flags != base_flags) - acpi_pci_osc_support(root, flags); + 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) {