From 21369c77477a7f937174833c8094154f0f995710 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 10 Feb 2014 13:36:26 +0100 Subject: [PATCH] ACPI / hotplug / PCI: Execute _EJ0 under the ACPI scan lock Since acpi_device_hotplug() assumes that ACPI handles of device objects passed to it will not become invalid while acpi_scan_lock is being held, make acpiphp_disable_slot() acquire acpi_scan_lock, because it generally causes _EJ0 to be executed for one of the devices in the slot and that may cause its ACPI handle to become invalid. Signed-off-by: Rafael J. Wysocki --- drivers/pci/hotplug/acpiphp_glue.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 11a6117fb358..fa8fe7441952 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -1007,9 +1007,15 @@ int acpiphp_disable_slot(struct acpiphp_slot *slot) { int ret; + /* + * Acquire acpi_scan_lock to ensure that the execution of _EJ0 in + * acpiphp_disable_and_eject_slot() will be synchronized properly. + */ + acpi_scan_lock_acquire(); pci_lock_rescan_remove(); ret = acpiphp_disable_and_eject_slot(slot); pci_unlock_rescan_remove(); + acpi_scan_lock_release(); return ret; } -- 2.11.0