2019-11-09 21:28:33

by Wolfram Sang

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

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 <[email protected]>
---
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


2019-11-11 10:28:38

by Niklas Söderlund

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

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 <[email protected]>

Reviewed-by: Niklas S?derlund <[email protected]>

> ---
> 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 S?derlund

2019-11-11 19:56:15

by Jean Delvare

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

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 <[email protected]>
> ---
> 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 <[email protected]>

--
Jean Delvare
SUSE L3 Support

2019-11-12 08:00:51

by Luca Ceresoli

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

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 <[email protected]>

[Tested on older kernel + TI serdes patches]
Tested-by: Luca Ceresoli <[email protected]>
Reviewed-by: Luca Ceresoli <[email protected]>

--
Luca

2019-11-12 08:20:10

by Geert Uytterhoeven

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

On Sat, Nov 9, 2019 at 10:26 PM Wolfram Sang
<[email protected]> 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 <[email protected]>

Reviewed-by: Geert Uytterhoeven <[email protected]>

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

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

2019-11-17 07:26:57

by Wolfram Sang

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

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 <[email protected]>

Applied to for-next, thanks!


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