From: Rafael J. Wysocki <rjw@xxxxxxx>
It generally is unsafe to call acpi_pci_osc_control_set() without
checking what _OSC bits the BIOS is willing to grant control of,
because control of some _OSC bits may be granted even if
acpi_pci_osc_control_set() returns AE_SUPPORT. Therefore make
acpi_get_hp_hw_control_from_firmware() use
acpi_pci_osc_control_query() to check if the BIOS will grant
OSC_SHPC_NATIVE_HP_CONTROL before calling acpi_pci_osc_control_set().
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/pci/hotplug/acpi_pcihp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
Index: linux-2.6/drivers/pci/hotplug/acpi_pcihp.c
===================================================================
--- linux-2.6.orig/drivers/pci/hotplug/acpi_pcihp.c
+++ linux-2.6/drivers/pci/hotplug/acpi_pcihp.c
@@ -358,11 +358,13 @@ int acpi_get_hp_hw_control_from_firmware
acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
dbg("Trying to get hotplug control for %s\n",
(char *)string.pointer);
+ status = acpi_pci_osc_control_query(handle, &flags);
+ if (ACPI_FAILURE(status)
+ || !(flags & OSC_SHPC_NATIVE_HP_CONTROL))
+ goto no_control;
status = acpi_pci_osc_control_set(handle, flags);
if (ACPI_SUCCESS(status))
goto got_one;
- if (status == AE_SUPPORT)
- goto no_control;
kfree(string.pointer);
string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
}
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