Re: [PATCH] ACPI / scan: Annotate physical_node_lock in acpi_scan_is_offline()

[Xie XiuQi <xiexiuqi@huawei.com>]

On 2015/4/11 7:31, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> acpi_scan_is_offline() may be called under the physical_node_lock
> of the given device object's parent, so prevent lockdep from
> complaining about that by annotating that instance with
> SINGLE_DEPTH_NESTING.
> 
> Reported-by: Xie XiuQi <xiexiuqi@huawei.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Tested-by: Xie XiuQi <xiexiuqi@huawei.com>

Thanks,
Xie XiuQi

> ---
>  drivers/acpi/scan.c |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -298,7 +298,11 @@ bool acpi_scan_is_offline(struct acpi_de
>  	struct acpi_device_physical_node *pn;
>  	bool offline = true;
>  
> -	mutex_lock(&adev->physical_node_lock);
> +	/*
> +	 * acpi_container_offline() calls this for all of the container's
> +	 * children under the container's physical_node_lock lock.
> +	 */
> +	mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
>  
>  	list_for_each_entry(pn, &adev->physical_node_list, node)
>  		if (device_supports_offline(pn->dev) && !pn->dev->offline) {
> 
> 
> .
>