[PATCH] i2c: remove helpers for ref-counting clients

[PATCH] i2c: remove helpers for ref-counting clients

[Wolfram Sang]

There are no in-tree users of these helpers anymore, and there
shouldn't. Most use cases went away once the driver model started to
refcount for us. There have been users like the media subsystem, but
they all switched to better refcounting methods meanwhile. Media did
this in 2008. Last user (IPMI) left 2018. Remove this cruft.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/i2c-core-base.c | 32 --------------------------------
 include/linux/i2c.h         |  3 ---
 2 files changed, 35 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 9c55d24c7a30..5a44a92ed1fb 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1743,38 +1743,6 @@ EXPORT_SYMBOL(i2c_del_driver);
 
 /* ------------------------------------------------------------------------- */
 
-/**
- * i2c_use_client - increments the reference count of the i2c client structure
- * @client: the client being referenced
- *
- * Each live reference to a client should be refcounted. The driver model does
- * that automatically as part of driver binding, so that most drivers don't
- * need to do this explicitly: they hold a reference until they're unbound
- * from the device.
- *
- * A pointer to the client with the incremented reference counter is returned.
- */
-struct i2c_client *i2c_use_client(struct i2c_client *client)
-{
-	if (client && get_device(&client->dev))
-		return client;
-	return NULL;
-}
-EXPORT_SYMBOL(i2c_use_client);
-
-/**
- * i2c_release_client - release a use of the i2c client structure
- * @client: the client being no longer referenced
- *
- * Must be called when a user of a client is finished with it.
- */
-void i2c_release_client(struct i2c_client *client)
-{
-	if (client)
-		put_device(&client->dev);
-}
-EXPORT_SYMBOL(i2c_release_client);
-
 struct i2c_cmd_arg {
 	unsigned	cmd;
 	void		*arg;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 8f512b992acd..23583f76c6dc 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -861,9 +861,6 @@ static inline bool i2c_client_has_driver(struct i2c_client *client)
 	return !IS_ERR_OR_NULL(client) && client->dev.driver;
 }
 
-extern struct i2c_client *i2c_use_client(struct i2c_client *client);
-extern void i2c_release_client(struct i2c_client *client);
-
 /* call the i2c_client->command() of all attached clients with
  * the given arguments */
 extern void i2c_clients_command(struct i2c_adapter *adap,
-- 
2.20.1

Re: [PATCH] i2c: remove helpers for ref-counting clients

[Niklas Söderlund]

Hi Wolfram,

Thanks for your work.

On 2019-11-09 22:26:15 +0100, Wolfram Sang wrote:
> There are no in-tree users of these helpers anymore, and there
> shouldn't. Most use cases went away once the driver model started to
> refcount for us. There have been users like the media subsystem, but
> they all switched to better refcounting methods meanwhile. Media did
> this in 2008. Last user (IPMI) left 2018. Remove this cruft.

Nice to clean out some old stuff :-)

> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> ---
>  drivers/i2c/i2c-core-base.c | 32 --------------------------------
>  include/linux/i2c.h         |  3 ---
>  2 files changed, 35 deletions(-)
> 
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 9c55d24c7a30..5a44a92ed1fb 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -1743,38 +1743,6 @@ EXPORT_SYMBOL(i2c_del_driver);
>  
>  /* ------------------------------------------------------------------------- */
>  
> -/**
> - * i2c_use_client - increments the reference count of the i2c client structure
> - * @client: the client being referenced
> - *
> - * Each live reference to a client should be refcounted. The driver model does
> - * that automatically as part of driver binding, so that most drivers don't
> - * need to do this explicitly: they hold a reference until they're unbound
> - * from the device.
> - *
> - * A pointer to the client with the incremented reference counter is returned.
> - */
> -struct i2c_client *i2c_use_client(struct i2c_client *client)
> -{
> -	if (client && get_device(&client->dev))
> -		return client;
> -	return NULL;
> -}
> -EXPORT_SYMBOL(i2c_use_client);
> -
> -/**
> - * i2c_release_client - release a use of the i2c client structure
> - * @client: the client being no longer referenced
> - *
> - * Must be called when a user of a client is finished with it.
> - */
> -void i2c_release_client(struct i2c_client *client)
> -{
> -	if (client)
> -		put_device(&client->dev);
> -}
> -EXPORT_SYMBOL(i2c_release_client);
> -
>  struct i2c_cmd_arg {
>  	unsigned	cmd;
>  	void		*arg;
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 8f512b992acd..23583f76c6dc 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -861,9 +861,6 @@ static inline bool i2c_client_has_driver(struct i2c_client *client)
>  	return !IS_ERR_OR_NULL(client) && client->dev.driver;
>  }
>  
> -extern struct i2c_client *i2c_use_client(struct i2c_client *client);
> -extern void i2c_release_client(struct i2c_client *client);
> -
>  /* call the i2c_client->command() of all attached clients with
>   * the given arguments */
>  extern void i2c_clients_command(struct i2c_adapter *adap,
> -- 
> 2.20.1
> 

-- 
Regards,
Niklas Söderlund

Re: [PATCH] i2c: remove helpers for ref-counting clients

[Jean Delvare]

On Sat,  9 Nov 2019 22:26:15 +0100, Wolfram Sang wrote:
> There are no in-tree users of these helpers anymore, and there
> shouldn't. Most use cases went away once the driver model started to
> refcount for us. There have been users like the media subsystem, but
> they all switched to better refcounting methods meanwhile. Media did
> this in 2008. Last user (IPMI) left 2018. Remove this cruft.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>  drivers/i2c/i2c-core-base.c | 32 --------------------------------
>  include/linux/i2c.h         |  3 ---
>  2 files changed, 35 deletions(-)
> 
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 9c55d24c7a30..5a44a92ed1fb 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -1743,38 +1743,6 @@ EXPORT_SYMBOL(i2c_del_driver);
>  
>  /* ------------------------------------------------------------------------- */
>  
> -/**
> - * i2c_use_client - increments the reference count of the i2c client structure
> - * @client: the client being referenced
> - *
> - * Each live reference to a client should be refcounted. The driver model does
> - * that automatically as part of driver binding, so that most drivers don't
> - * need to do this explicitly: they hold a reference until they're unbound
> - * from the device.
> - *
> - * A pointer to the client with the incremented reference counter is returned.
> - */
> -struct i2c_client *i2c_use_client(struct i2c_client *client)
> -{
> -	if (client && get_device(&client->dev))
> -		return client;
> -	return NULL;
> -}
> -EXPORT_SYMBOL(i2c_use_client);
> -
> -/**
> - * i2c_release_client - release a use of the i2c client structure
> - * @client: the client being no longer referenced
> - *
> - * Must be called when a user of a client is finished with it.
> - */
> -void i2c_release_client(struct i2c_client *client)
> -{
> -	if (client)
> -		put_device(&client->dev);
> -}
> -EXPORT_SYMBOL(i2c_release_client);
> -
>  struct i2c_cmd_arg {
>  	unsigned	cmd;
>  	void		*arg;
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 8f512b992acd..23583f76c6dc 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -861,9 +861,6 @@ static inline bool i2c_client_has_driver(struct i2c_client *client)
>  	return !IS_ERR_OR_NULL(client) && client->dev.driver;
>  }
>  
> -extern struct i2c_client *i2c_use_client(struct i2c_client *client);
> -extern void i2c_release_client(struct i2c_client *client);
> -
>  /* call the i2c_client->command() of all attached clients with
>   * the given arguments */
>  extern void i2c_clients_command(struct i2c_adapter *adap,

Sweet!

Reviewed-by: Jean Delvare <jdelvare@suse.de>

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH] i2c: remove helpers for ref-counting clients

[Luca Ceresoli]

Hi,

On 09/11/19 22:26, Wolfram Sang wrote:
> There are no in-tree users of these helpers anymore, and there
> shouldn't. Most use cases went away once the driver model started to
> refcount for us. There have been users like the media subsystem, but
> they all switched to better refcounting methods meanwhile. Media did
> this in 2008. Last user (IPMI) left 2018. Remove this cruft.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

[Tested on older kernel + TI serdes patches]
Tested-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>

-- 
Luca

Re: [PATCH] i2c: remove helpers for ref-counting clients

[Geert Uytterhoeven]

On Sat, Nov 9, 2019 at 10:26 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> There are no in-tree users of these helpers anymore, and there
> shouldn't. Most use cases went away once the driver model started to
> refcount for us. There have been users like the media subsystem, but
> they all switched to better refcounting methods meanwhile. Media did
> this in 2008. Last user (IPMI) left 2018. Remove this cruft.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] i2c: remove helpers for ref-counting clients

[Wolfram Sang]

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On Sat, Nov 09, 2019 at 10:26:15PM +0100, Wolfram Sang wrote:
> There are no in-tree users of these helpers anymore, and there
> shouldn't. Most use cases went away once the driver model started to
> refcount for us. There have been users like the media subsystem, but
> they all switched to better refcounting methods meanwhile. Media did
> this in 2008. Last user (IPMI) left 2018. Remove this cruft.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Applied to for-next, thanks!


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