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PCI/ACPI: Clarify message about _OSC failure 

This message:

  acpi PNP0A08:02: _OSC failed (AE_NOT_FOUND); disabling ASPM

is alarming and slightly misleading.  Per the PCI Firmware Spec, r3.2, sec
4.5.1, _OSC is required for PCIe hierarchies.  If _OSC is absent or fails,
the OS must not attempt to use any of the features defined for _OSC.  That
includes native hotplug, native PME, AER, and other things as well as ASPM.

Rephrase the message to:

  acpi PNP0A08:02: _OSC: platform retains control of PCIe features (AE_NOT_FOUND)

Previous discussion at https://lore.kernel.org/r/20200602223618.GA845676@bjorn-Precision-5520/

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
master
Bjorn Helgaas 2020-06-02 16:42:33 -05:00
parent 866e61fc40
commit 508d392ae0
1 changed files with 3 additions and 4 deletions
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7
drivers/acpi/pci_root.c
View File

@ -441,9 +441,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
if ((status == AE_NOT_FOUND) && !is_pcie)
return;
dev_info(&device->dev, "_OSC failed (%s)%s\n",
acpi_format_exception(status),
pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
acpi_format_exception(status));
return;
}
@ -499,7 +498,7 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
} else {
decode_osc_control(root, "OS requested", requested);
decode_osc_control(root, "platform willing to grant", control);
dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
acpi_format_exception(status));
/*