Re: [PATCH] docs: i2c: Fix return value of i2c_smbus_xxx functions

From: Peter Rosin
Date: Tue Nov 19 2019 - 04:33:10 EST


On 2019-11-19 09:56, Lei YU wrote:
> In i2c/dev-interface.rst it said
>
>> All these transactions return -1 on failure
>
> But actually the i2c_smbus_xxx functions return negative error numbers
> on failure, instead of -1.
>
> Fix the document.
>
> Signed-off-by: Lei YU <mine260309@xxxxxxxxx>
> ---
> Documentation/i2c/dev-interface.rst | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/i2c/dev-interface.rst b/Documentation/i2c/dev-interface.rst
> index 69c23a3..73b77c3 100644
> --- a/Documentation/i2c/dev-interface.rst
> +++ b/Documentation/i2c/dev-interface.rst
> @@ -163,8 +163,8 @@ for details) through the following functions::
> __s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
> __u8 *values);
>
> -All these transactions return -1 on failure; you can read errno to see
> -what happened. The 'write' transactions return 0 on success; the
> +All these transactions return negative value on failure; you can read errno to
> +see what happened. The 'write' transactions return 0 on success; the

s/return negative/return a negative/

And the line is now too long compared to the rest of the text, so you
need to rewrap the paragraph.

And why do you need to dig around in errno if the negative errno has
already been returned?

> 'read' transactions return the read value, except for read_block, which
> returns the number of values read. The block buffers need not be longer
> than 32 bytes.
>

Hmm, unrelated, but should that perhaps be "must not" instead of "need not"?

Cheers,
Peter