[PATCH v2] Do not disable driver and bus shutdown hook when class shutdown hook is set.

From: Michal Suchanek
Date: Fri Aug 11 2017 - 09:44:54 EST


As seen from the implementation of the single class shutdown hook this
is not very sound design.

Rename the class shutdown hook to shutdown_pre to make it clear it runs
before the driver shutdown hook.

Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
---
v2: rename class shutdown member to shutdown_pre
---
drivers/base/core.c | 9 +++++----
drivers/char/tpm/tpm-chip.c | 11 ++---------
include/linux/device.h | 4 ++--
3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 755451f684bc..13e7c41fd417 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2664,11 +2664,12 @@ void device_shutdown(void)
pm_runtime_get_noresume(dev);
pm_runtime_barrier(dev);

- if (dev->class && dev->class->shutdown) {
+ if (dev->class && dev->class->shutdown_pre) {
if (initcall_debug)
- dev_info(dev, "shutdown\n");
- dev->class->shutdown(dev);
- } else if (dev->bus && dev->bus->shutdown) {
+ dev_info(dev, "shutdown_pre\n");
+ dev->class->shutdown_pre(dev);
+ }
+ if (dev->bus && dev->bus->shutdown) {
if (initcall_debug)
dev_info(dev, "shutdown\n");
dev->bus->shutdown(dev);
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 67ec9d3d04f5..0eca20c5a80c 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -164,14 +164,7 @@ static int tpm_class_shutdown(struct device *dev)
chip->ops = NULL;
up_write(&chip->ops_sem);
}
- /* Allow bus- and device-specific code to run. Note: since chip->ops
- * is NULL, more-specific shutdown code will not be able to issue TPM
- * commands.
- */
- if (dev->bus && dev->bus->shutdown)
- dev->bus->shutdown(dev);
- else if (dev->driver && dev->driver->shutdown)
- dev->driver->shutdown(dev);
+
return 0;
}

@@ -214,7 +207,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
device_initialize(&chip->devs);

chip->dev.class = tpm_class;
- chip->dev.class->shutdown = tpm_class_shutdown;
+ chip->dev.class->shutdown_pre = tpm_class_shutdown;
chip->dev.release = tpm_dev_release;
chip->dev.parent = pdev;
chip->dev.groups = chip->groups;
diff --git a/include/linux/device.h b/include/linux/device.h
index beabdbc08420..649b1b72c76a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -375,7 +375,7 @@ int subsys_virtual_register(struct bus_type *subsys,
* @suspend: Used to put the device to sleep mode, usually to a low power
* state.
* @resume: Used to bring the device from the sleep mode.
- * @shutdown: Called at shut-down time to quiesce the device.
+ * @shutdown_pre: Called at shut-down time before driver shutdown.
* @ns_type: Callbacks so sysfs can detemine namespaces.
* @namespace: Namespace of the device belongs to this class.
* @pm: The default device power management operations of this class.
@@ -404,7 +404,7 @@ struct class {

int (*suspend)(struct device *dev, pm_message_t state);
int (*resume)(struct device *dev);
- int (*shutdown)(struct device *dev);
+ int (*shutdown_pre)(struct device *dev);

const struct kobj_ns_type_operations *ns_type;
const void *(*namespace)(struct device *dev);
--
2.10.2