Re: [PATCH 3/6] Update soc driver to use new ida helper functions

[Lee Duncan <lduncan@suse.com>]

Oops. I see the subject is wrong on this patch.

I will wait for comments (if any) then re-submit the sequence.

On 09/06/2015 10:59 AM, Lee Duncan wrote:
> This simplifies the calling sequence to
> acquire and to release an ida-managed index.
> 
> Note that the ida_destroy() calls here previously
> had no locking, so this may close a race condition
> when errors occur or when removing a soc.
> 
> Signed-off-by: Lee Duncan <lduncan@suse.com>
> ---
>  drivers/base/soc.c | 17 +++--------------
>  1 file changed, 3 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/base/soc.c b/drivers/base/soc.c
> index 39fca01c8fa1..7b632f086524 100644
> --- a/drivers/base/soc.c
> +++ b/drivers/base/soc.c
> @@ -122,18 +122,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr
>  	}
>  
>  	/* Fetch a unique (reclaimable) SOC ID. */
> -	do {
> -		if (!ida_pre_get(&soc_ida, GFP_KERNEL)) {
> -			ret = -ENOMEM;
> -			goto out2;
> -		}
> -
> -		spin_lock(&soc_lock);
> -		ret = ida_get_new(&soc_ida, &soc_dev->soc_dev_num);
> -		spin_unlock(&soc_lock);
> -
> -	} while (ret == -EAGAIN);
> -
> +	ret = ida_get_index(&soc_ida, &soc_lock, &soc_dev->soc_dev_num);
>  	if (ret)
>  		goto out2;
>  
> @@ -151,7 +140,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr
>  	return soc_dev;
>  
>  out3:
> -	ida_remove(&soc_ida, soc_dev->soc_dev_num);
> +	ida_put_index(&soc_ida, &sock_lock, soc_dev->soc_dev_num);
>  out2:
>  	kfree(soc_dev);
>  out1:
> @@ -161,7 +150,7 @@ out1:
>  /* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
>  void soc_device_unregister(struct soc_device *soc_dev)
>  {
> -	ida_remove(&soc_ida, soc_dev->soc_dev_num);
> +	ida_put_index(&soc_ida, &sock_lock, soc_dev->soc_dev_num);
>  
>  	device_unregister(&soc_dev->dev);
>  }
> 

-- 
Lee Duncan
SUSE Labs