PCI: acpi_pcihp: run _OSC on a root bridge
_OSC should be ran on a root bridge instead of the device itself. Do
this before touching OSHP since PCI fw specs states that _OSC should be
preferred over OSHP (however if the device has OSHP but not _OSC -- not
a root bridge -- it's not).
Cc: kristen.c.accardi@intel.com
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index 93e37f0..bd83197 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -382,7 +382,7 @@
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
{
acpi_status status;
- acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+ acpi_handle chandle, handle;
struct pci_dev *pdev = dev;
struct pci_bus *parent;
struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
@@ -399,10 +399,28 @@
* Per PCI firmware specification, we should run the ACPI _OSC
* method to get control of hotplug hardware before using it. If
* an _OSC is missing, we look for an OSHP to do the same thing.
- * To handle different BIOS behavior, we look for _OSC and OSHP
- * within the scope of the hotplug controller and its parents,
+ * To handle different BIOS behavior, we look for _OSC on a root
+ * bridge preferentially (according to PCI fw spec). Later for
+ * OSHP within the scope of the hotplug controller and its parents,
* upto the host bridge under which this controller exists.
*/
+ while (pdev->bus->self)
+ pdev = pdev->bus->self;
+ handle = acpi_get_pci_rootbridge_handle(pci_domain_nr(pdev->bus),
+ pdev->bus->number);
+ if (handle) {
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+ dbg("Trying to get hotplug control for %s\n",
+ (char *)string.pointer);
+ status = pci_osc_control_set(handle, flags);
+ if (ACPI_SUCCESS(status))
+ goto got_one;
+ kfree(string.pointer);
+ string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
+ }
+
+ pdev = dev;
+ handle = DEVICE_ACPI_HANDLE(&dev->dev);
while (!handle) {
/*
* This hotplug controller was not listed in the ACPI name
@@ -427,15 +445,9 @@
acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
dbg("Trying to get hotplug control for %s \n",
(char *)string.pointer);
- status = pci_osc_control_set(handle, flags);
- if (status == AE_NOT_FOUND)
- status = acpi_run_oshp(handle);
- if (ACPI_SUCCESS(status)) {
- dbg("Gained control for hotplug HW for pci %s (%s)\n",
- pci_name(dev), (char *)string.pointer);
- kfree(string.pointer);
- return 0;
- }
+ status = acpi_run_oshp(handle);
+ if (ACPI_SUCCESS(status))
+ goto got_one;
if (acpi_root_bridge(handle))
break;
chandle = handle;
@@ -449,6 +461,11 @@
kfree(string.pointer);
return -ENODEV;
+got_one:
+ dbg("Gained control for hotplug HW for pci %s (%s)\n", pci_name(dev),
+ (char *)string.pointer);
+ kfree(string.pointer);
+ return 0;
}
EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);