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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-02-03 02:22:17 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-02-03 22:28:18 +0100
commitf41b32613138ae05329a0f0e7170223b775d6b24 (patch)
tree9bc5cefef02934ca2a7fdb5308a58cf49909ea01
parent2d7c1b77dd59387070aab355532dd157f888325c (diff)
downloadop-kernel-dev-f41b32613138ae05329a0f0e7170223b775d6b24.zip
op-kernel-dev-f41b32613138ae05329a0f0e7170223b775d6b24.tar.gz
ACPI / hotplug / PCI: Move PCI rescan-remove locking to hotplug_event()
Commit 9217a984671e (ACPI / hotplug / PCI: Use global PCI rescan-remove locking) modified ACPIPHP to protect its PCI device removal and addition code paths from races against sysfs-driven rescan and remove operations with the help of PCI rescan-remove locking. However, it overlooked the fact that hotplug_event_work() is not the only caller of hotplug_event() which may also be called by dock_hotplug_event() and that code path is missing the PCI rescan-remove locking. This means that, although the PCI rescan-remove lock is held as appropriate during the handling of events originating from handle_hotplug_event(), the ACPIPHP's operations resulting from dock events may still suffer the race conditions that commit 9217a984671e was supposed to eliminate. To address that problem, move the PCI rescan-remove locking from hotplug_event_work() to hotplug_event() so that it is used regardless of the way that function is invoked. Revamps: 9217a984671e (ACPI / hotplug / PCI: Use global PCI rescan-remove locking) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
-rw-r--r--drivers/pci/hotplug/acpiphp_glue.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 6a4b4b7..6e5bd79 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -852,6 +852,7 @@ static void hotplug_event(acpi_handle handle, u32 type, void *data)
mutex_unlock(&acpiphp_context_lock);
+ pci_lock_rescan_remove();
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
switch (type) {
@@ -905,6 +906,7 @@ static void hotplug_event(acpi_handle handle, u32 type, void *data)
break;
}
+ pci_unlock_rescan_remove();
if (bridge)
put_bridge(bridge);
}
@@ -915,11 +917,9 @@ static void hotplug_event_work(void *data, u32 type)
acpi_handle handle = context->handle;
acpi_scan_lock_acquire();
- pci_lock_rescan_remove();
hotplug_event(handle, type, context);
- pci_unlock_rescan_remove();
acpi_scan_lock_release();
acpi_evaluate_hotplug_ost(handle, type, ACPI_OST_SC_SUCCESS, NULL);
put_bridge(context->func.parent);
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