[PATCH 1/5] driver core: separate function to shutdown one device

[Pasha Tatashin]

On 04-20 11:26, David Jeffery wrote:
> Make a separate function for the part of device_shutdown() that does the
> shutown for a single device.  This is in preparation for making device
> shutdown asynchronous.
> 
> Signed-off-by: Stuart Hayes <stuart.w.hayes at gmail.com>
> Signed-off-by: David Jeffery <djeffery at redhat.com>
> Tested-by: Laurence Oberman <loberman at redhat.com>
> ---
>  drivers/base/core.c | 71 +++++++++++++++++++++++++--------------------
>  1 file changed, 39 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 0613de0fbe44..5353c6c22d49 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4783,12 +4783,48 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
>  	return error;
>  }
>  
> +static void shutdown_one_device(struct device *dev)
> +{
> +	struct device *parent = dev->parent;
> +
> +	/* hold lock to avoid race with probe/release */
> +	if (parent)
> +		device_lock(parent);
> +	device_lock(dev);
> +
> +	/* Don't allow any more runtime suspends */
> +	pm_runtime_get_noresume(dev);
> +	pm_runtime_barrier(dev);
> +
> +	if (dev->class && dev->class->shutdown_pre) {
> +		if (initcall_debug)
> +			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);
> +	} else if (dev->driver && dev->driver->shutdown) {
> +		if (initcall_debug)
> +			dev_info(dev, "shutdown\n");
> +		dev->driver->shutdown(dev);
> +	}
> +
> +	device_unlock(dev);
> +	if (parent)
> +		device_unlock(parent);
> +
> +	put_device(parent);
> +	put_device(dev);
> +}

Reviewed-by: Pasha Tatashin <pasha.tatashin at soleen.com> 

Also, please CC: kexec at lists.infradead.org, this series helps the live 
update, and kexec performance.

Pasha