kernel/pci-_osc-supported-field-should-contain-supported-features-not-enabled-ones.patch
2010-12-10 17:50:24 -05:00

67 lines
2.6 KiB
Diff

commit 885c252ffb059dc493200bdb981bdd21cabe4442
Author: Matthew Garrett <mjg@redhat.com>
Date: Thu Dec 9 18:31:59 2010 -0500
PCI: _OSC "supported" field should contain supported features, not enabled ones
From testing with Windows, the call to the PCI root _OSC method includes
the full set of features supported by the operating system even if the
hardware has already indicated that it doesn't support ASPM or MSI.
https://bugzilla.redhat.com/show_bug.cgi?id=638912 is a case where making
the _OSC call will incorrectly configure the chipset unless the supported
field has bits 1, 2 and 4 set. Rework the functionality to ensure that
we match this behaviour.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 96668ad..afb5d08 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -450,7 +450,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
struct acpi_pci_root *root;
acpi_handle handle;
struct acpi_device *child;
- u32 flags, base_flags;
+ u32 flags;
root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
if (!root)
@@ -498,10 +498,15 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
device->driver_data = root;
/*
- * All supported architectures that use ACPI have support for
- * PCI domains, so we indicate this in _OSC support capabilities.
+ * Indicate support for various _OSC capabilities. These match
+ * what the operating system supports, not what the hardware supports,
+ * so they shouldn't be conditional on functionality that's been
+ * blacklisted
*/
- flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
+ flags = OSC_EXT_PCI_CONFIG_SUPPORT | OSC_ACTIVE_STATE_PWR_SUPPORT |
+ OSC_CLOCK_PWR_CAPABILITY_SUPPORT |
+ OSC_PCI_SEGMENT_GROUPS_SUPPORT | OSC_MSI_SUPPORT;
+
acpi_pci_osc_support(root, flags);
/*
@@ -555,17 +560,6 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
list_for_each_entry(child, &device->children, node)
acpi_pci_bridge_scan(child);
- /* Indicate support for various _OSC capabilities. */
- if (pci_ext_cfg_avail(root->bus->self))
- flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
- if (pcie_aspm_enabled())
- flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
- OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
- if (pci_msi_enabled())
- flags |= OSC_MSI_SUPPORT;
- if (flags != base_flags)
- acpi_pci_osc_support(root, flags);
-
pci_acpi_add_bus_pm_notifier(device, root->bus);
if (device->wakeup.flags.run_wake)
device_set_run_wake(root->bus->bridge, true);