Re: [PATCH] cxl/mem: Clarify UAPI documentation

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Tue, 13 Apr 2021 07:32:47 -0700
Ben Widawsky <ben.widawsky@intel.com> wrote:

> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>

Sensible update.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  include/uapi/linux/cxl_mem.h | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
> index f6e8a005b113..8dd516ddb098 100644
> --- a/include/uapi/linux/cxl_mem.h
> +++ b/include/uapi/linux/cxl_mem.h
> @@ -81,6 +81,13 @@ static const struct {
>   *  - @size_in = -1
>   *  - @size_out = 0
>   *
> + * Commands which have a variable length input likely have a minimum length.
> + * This is not enforced by the UAPI, and therefore might look like the command
> + * succeeded when sending too small of an input payload. Caution should be taken
> + * by checking the @cxl_send_command.retval for such cases. For commands with a
> + * variable length output, the caller is free to consume as little or as much as
> + * they want.
> + *
>   * See struct cxl_mem_query_commands.
>   */
>  struct cxl_command_info {