Re: [PATCH v3 8/9] driver core: Correct API device_for_each_child_reverse_from() prototype

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Thu, 12 Dec 2024 21:38:44 +0800
Zijun Hu <zijun_hu@icloud.com> wrote:

> From: Zijun Hu <quic_zijuhu@quicinc.com>
> 
> For API device_for_each_child_reverse_from(..., const void *data,
> 		int (*fn)(struct device *dev, const void *data))
> 
> - Type of @data is const pointer, and means caller's data @*data is not
>   allowed to be modified, but that usually is not proper for such non
>   finding device iterating API.
> 
> - Types for both @data and @fn are not consistent with all other
>   for_each device iterating APIs device_for_each_child(_reverse)(),
>   bus_for_each_dev() and (driver|class)_for_each_device().
> 
> Correct its prototype by removing const from parameter types, then adapt
> for various existing usages.
> 
> An dedicated typedef device_iter_t will be introduced as @fn() type for
> various for_each device interating APIs later.
> 
> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
This inconsistency is indeed weird.  So this changes seems reasonable to me.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Dan, this was your function. There is nothing about the const
in the original commit.  Did you intend it to be different from
device_for_each_child_reverse() etc?

Jonathan

> ---
>  drivers/base/core.c       | 4 ++--
>  drivers/cxl/core/hdm.c    | 2 +-
>  drivers/cxl/core/region.c | 2 +-
>  include/linux/device.h    | 4 ++--
>  4 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 34fb13f914b3db47e6a047fdabf3c9b18ecc08cc..7be9c732bec1b060a477b362f555c3e87c8c7b91 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4043,8 +4043,8 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
>   * device_for_each_child_reverse_from();
>   */
>  int device_for_each_child_reverse_from(struct device *parent,
> -				       struct device *from, const void *data,
> -				       int (*fn)(struct device *, const void *))
> +				       struct device *from, void *data,
> +				       int (*fn)(struct device *, void *))
>  {
>  	struct klist_iter i;
>  	struct device *child;
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 28edd5822486851912393f066478252b20abc19d..50e6a45b30ba260c066a0781b9ed3a2f6f3462d7 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -703,7 +703,7 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
>  	return 0;
>  }
>  
> -static int commit_reap(struct device *dev, const void *data)
> +static int commit_reap(struct device *dev, void *data)
>  {
>  	struct cxl_port *port = to_cxl_port(dev->parent);
>  	struct cxl_decoder *cxld;
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index bfecd71040c2f4373645380b4c31327d8b42d095..a4cff4c266e7a7dd6a3feb1513bf14b7d3f9afa2 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -778,7 +778,7 @@ static size_t show_targetN(struct cxl_region *cxlr, char *buf, int pos)
>  	return rc;
>  }
>  
> -static int check_commit_order(struct device *dev, const void *data)
> +static int check_commit_order(struct device *dev, void *data)
>  {
>  	struct cxl_decoder *cxld = to_cxl_decoder(dev);
>  
> diff --git a/include/linux/device.h b/include/linux/device.h
> index a9d928398895b062094b94f2c188cbe9951d7ac1..025bac08fca7b2513acb1fbcb666be1dc64f03d1 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -1079,8 +1079,8 @@ int device_for_each_child(struct device *parent, void *data,
>  int device_for_each_child_reverse(struct device *parent, void *data,
>  				  int (*fn)(struct device *dev, void *data));
>  int device_for_each_child_reverse_from(struct device *parent,
> -				       struct device *from, const void *data,
> -				       int (*fn)(struct device *, const void *));
> +				       struct device *from, void *data,
> +				       int (*fn)(struct device *, void *));
>  struct device *device_find_child(struct device *parent, const void *data,
>  				 device_match_t match);
>  struct device *device_find_child_by_name(struct device *parent,
>