Hi Wolfram,
On 13/03/2019 16:55, Wolfram Sang wrote:
> From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>
> Currently i2c_new_device and i2c_new_dummy return just NULL in error
> case although they have more error details internally. Therefore move
> the functionality into new functions returning detailed errors and
> add wrappers for compatibility with the current API.
>
> This allows to use these functions with detailed error codes within
> the i2c core or for API extensions.
>
> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> [wsa: rename new functions to 'errptr' style and fix minor kdoc issues]
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
As mentioned in 2/3, the _errptr suffix here feels a bit
'hungarian-notation', but I can see how we would want a good clear
distinction between the two types, otherwise we might see people adding
code that checks for ERR_PTR() using the non-errptr functions.
Perhaps that's not really an issue if it's caught by review, or
coccinelle though.
Aside from the function-name-bike-shedding which can be handled as you
wished/discussed in 2/3, and one small grammatical fix in a comment below:
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/i2c/i2c-core-base.c | 70 ++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 57 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index cb6c5cb0df0b..bbca2e8bb019 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -710,7 +710,7 @@ static int i2c_dev_irq_from_resources(const struct resource *resources,
> }
>
> /**
> - * i2c_new_device - instantiate an i2c device
> + * i2c_new_device_errptr - instantiate an i2c device
> * @adap: the adapter managing the device
> * @info: describes one I2C device; bus_num is ignored
> * Context: can sleep
> @@ -723,17 +723,17 @@ static int i2c_dev_irq_from_resources(const struct resource *resources,
> * before any i2c_adapter could exist.
> *
> * This returns the new i2c client, which may be saved for later use with
> - * i2c_unregister_device(); or NULL to indicate an error.
> + * i2c_unregister_device(); or an ERR_PTR to describe the error.
> */
> -struct i2c_client *
> -i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
> +static struct i2c_client *
> +i2c_new_device_errptr(struct i2c_adapter *adap, struct i2c_board_info const *info)
> {
> struct i2c_client *client;
> int status;
>
> client = kzalloc(sizeof *client, GFP_KERNEL);
> if (!client)
> - return NULL;
> + return ERR_PTR(-ENOMEM);
>
> client->adapter = adap;
>
> @@ -799,7 +799,29 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
> client->name, client->addr, status);
> out_err_silent:
> kfree(client);
> - return NULL;
> + return ERR_PTR(status);
> +}
> +
> +/**
> + * i2c_new_device - instantiate an i2c device
> + * @adap: the adapter managing the device
> + * @info: describes one I2C device; bus_num is ignored
> + * Context: can sleep
> + *
> + * This function has the same functionality like i2c_new_device_errptr, it just
s/like/as/
> + * returns NULL instead of an ERR_PTR in case of an error for compatibility
> + * with current I2C API.
> + *
> + * This returns the new i2c client, which may be saved for later use with
> + * i2c_unregister_device(); or NULL to indicate an error.
> + */
> +struct i2c_client *
> +i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
> +{
> + struct i2c_client *ret;
> +
> + ret = i2c_new_device_errptr(adap, info);
> + return IS_ERR(ret) ? NULL : ret;
> }
> EXPORT_SYMBOL_GPL(i2c_new_device);
>
> @@ -850,7 +872,7 @@ static struct i2c_driver dummy_driver = {
> };
>
> /**
> - * i2c_new_dummy - return a new i2c device bound to a dummy driver
> + * i2c_new_dummy_errptr - return a new i2c device bound to a dummy driver
> * @adapter: the adapter managing the device
> * @address: seven bit address to be used
> * Context: can sleep
> @@ -865,15 +887,37 @@ static struct i2c_driver dummy_driver = {
> * different driver.
> *
> * This returns the new i2c client, which should be saved for later use with
> - * i2c_unregister_device(); or NULL to indicate an error.
> + * i2c_unregister_device(); or an ERR_PTR to describe the error.
> */
> -struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
> +static struct i2c_client *
> +i2c_new_dummy_errptr(struct i2c_adapter *adapter, u16 address)
> {
> struct i2c_board_info info = {
> I2C_BOARD_INFO("dummy", address),
> };
>
> - return i2c_new_device(adapter, &info);
> + return i2c_new_device_errptr(adapter, &info);
> +}
> +
> +/**
> + * i2c_new_dummy - return a new i2c device bound to a dummy driver
> + * @adapter: the adapter managing the device
> + * @address: seven bit address to be used
> + * Context: can sleep
> + *
> + * This function has the same functionality like i2c_new_dummy_errptr, it just
> + * returns NULL instead of an ERR_PTR in case of an error for compatibility
> + * with current I2C API.
> + *
> + * This returns the new i2c client, which should be saved for later use with
> + * i2c_unregister_device(); or NULL to indicate an error.
> + */
> +struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
> +{
> + struct i2c_client *ret;
> +
> + ret = i2c_new_dummy_errptr(adapter, address);
> + return IS_ERR(ret) ? NULL : ret;
> }
> EXPORT_SYMBOL_GPL(i2c_new_dummy);
>
> @@ -996,9 +1040,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
> info.flags |= I2C_CLIENT_SLAVE;
> }
>
> - client = i2c_new_device(adap, &info);
> - if (!client)
> - return -EINVAL;
> + client = i2c_new_device_errptr(adap, &info);
> + if (IS_ERR(client))
> + return PTR_ERR(client);
>
> /* Keep track of the added device */
> mutex_lock(&adap->userspace_clients_lock);
>
