From e0ae8fee0e11c1a8e9b45ab14ab5fe58d87f031d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 30 Aug 2013 14:19:29 +0200 Subject: [PATCH] ACPI / scan: Change ordering of locks for device hotplug Change the ordering of device hotplug locks in scan.c so that acpi_scan_lock is always acquired after device_hotplug_lock. This will make it possible to use device_hotplug_lock around some code paths that acquire acpi_scan_lock safely (most importantly system suspend and hibernation). Apart from that, acpi_scan_lock is platform-specific and device_hotplug_lock is general, so the new ordering appears to be more appropriate from the overall design viewpoint. Signed-off-by: Rafael J. Wysocki Acked-by: Toshi Kani --- drivers/acpi/scan.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index e2f6d9dbdf0d..42982b522b36 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -207,8 +207,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device) return -EINVAL; } - lock_device_hotplug(); - /* * Carry out two passes here and ignore errors in the first pass, * because if the devices in question are memory blocks and @@ -239,9 +237,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device) ACPI_UINT32_MAX, acpi_bus_online_companions, NULL, NULL, NULL); - - unlock_device_hotplug(); - put_device(&device->dev); return -EBUSY; } @@ -252,8 +247,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device) acpi_bus_trim(device); - unlock_device_hotplug(); - /* Device node has been unregistered. */ put_device(&device->dev); device = NULL; @@ -309,6 +302,7 @@ static void acpi_bus_device_eject(void *context) u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; int error; + lock_device_hotplug(); mutex_lock(&acpi_scan_lock); acpi_bus_get_device(handle, &device); @@ -332,6 +326,7 @@ static void acpi_bus_device_eject(void *context) out: mutex_unlock(&acpi_scan_lock); + unlock_device_hotplug(); return; err_out: @@ -346,8 +341,8 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source) u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; int error; - mutex_lock(&acpi_scan_lock); lock_device_hotplug(); + mutex_lock(&acpi_scan_lock); if (ost_source != ACPI_NOTIFY_BUS_CHECK) { acpi_bus_get_device(handle, &device); @@ -373,9 +368,9 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source) kobject_uevent(&device->dev.kobj, KOBJ_ONLINE); out: - unlock_device_hotplug(); acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL); mutex_unlock(&acpi_scan_lock); + unlock_device_hotplug(); } static void acpi_scan_bus_check(void *context) @@ -466,6 +461,7 @@ void acpi_bus_hot_remove_device(void *context) acpi_handle handle = device->handle; int error; + lock_device_hotplug(); mutex_lock(&acpi_scan_lock); error = acpi_scan_hot_remove(device); @@ -475,6 +471,7 @@ void acpi_bus_hot_remove_device(void *context) NULL); mutex_unlock(&acpi_scan_lock); + unlock_device_hotplug(); kfree(context); } EXPORT_SYMBOL(acpi_bus_hot_remove_device); -- 2.11.0