Hi Daniel,
Thank you for the patch.
On Mon, Jan 18, 2021 at 12:34:25AM +0000, Daniel Scally wrote:
> We want to refer to an i2c device by name before it has been
s/i2c device/acpi i2c device/ ?
> created by the kernel; add a function that constructs the name
> from the acpi device instead.
>
> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
> ---
> Changes in v2:
>
> - Stopped using devm_kasprintf()
>
> drivers/i2c/i2c-core-acpi.c | 16 ++++++++++++++++
> include/linux/i2c.h | 5 +++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
> index 37c510d9347a..98c3ba9a2350 100644
> --- a/drivers/i2c/i2c-core-acpi.c
> +++ b/drivers/i2c/i2c-core-acpi.c
> @@ -497,6 +497,22 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
> }
> EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
>
> +/**
> + * i2c_acpi_dev_name - Construct i2c device name for devs sourced from ACPI
> + * @adev: ACPI device to construct the name for
> + *
> + * Constructs the name of an i2c device matching the format used by
> + * i2c_dev_set_name() to allow users to refer to an i2c device by name even
> + * before they have been instantiated.
> + *
> + * The caller is responsible for freeing the returned pointer.
> + */
> +char *i2c_acpi_dev_name(struct acpi_device *adev)
> +{
> + return kasprintf(GFP_KERNEL, I2C_DEV_NAME_FORMAT, acpi_dev_name(adev));
There's a real danger of a memory leak, as the function name sounds very
similar to dev_name() or acpi_dev_name() and those don't allocate
memory. I'm not sure what a better name would be, but given that this
function is only used in patch 6/7 and not in the I2C subsystem itself,
I wonder if we should inline this kasprintf() call in the caller and
drop this patch.
> +}
> +EXPORT_SYMBOL_GPL(i2c_acpi_dev_name);
> +
> #ifdef CONFIG_ACPI_I2C_OPREGION
> static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
> u8 cmd, u8 *data, u8 data_len)
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 4d40a4b46810..b82aac05b17f 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -998,6 +998,7 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
> u32 i2c_acpi_find_bus_speed(struct device *dev);
> struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
> struct i2c_board_info *info);
> +char *i2c_acpi_dev_name(struct acpi_device *adev);
> struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
> #else
> static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
> @@ -1014,6 +1015,10 @@ static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
> {
> return ERR_PTR(-ENODEV);
> }
> +static inline char *i2c_acpi_dev_name(struct acpi_device *adev)
> +{
> + return NULL;
> +}
> static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
> {
> return NULL;
--
Regards,
Laurent Pinchart
