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

From: Jarkko Sakkinen
Date: Sat Aug 19 2017 - 08:04:16 EST


On Fri, Aug 11, 2017 at 03:44:43PM +0200, Michal Suchanek wrote:
> 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>

I already gave this reviewed-by but cannot apply it because there's no
ack from device maintainers yet.

/Jarkko

> ---
> 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
>