[libcamera-devel] [PATCH 21/31] libcamera: ipa: Support array controls in ipa_control_value_entry

[Kieran Bingham]

Hi Laurent,

On 29/02/2020 16:42, Laurent Pinchart wrote:
> Report in a new field of the ipa_control_value_entry structure if the
> value contains an array. Reorganize the other fields of the structure to
> avoid increasing its size.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

With comments below addressed:

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> ---
>  include/ipa/ipa_controls.h     | 6 ++++--
>  src/libcamera/ipa_controls.cpp | 4 ++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/include/ipa/ipa_controls.h b/include/ipa/ipa_controls.h
> index 6371e34575f2..37f97d6ad2a4 100644
> --- a/include/ipa/ipa_controls.h
> +++ b/include/ipa/ipa_controls.h
> @@ -26,9 +26,11 @@ struct ipa_controls_header {
>  
>  struct ipa_control_value_entry {
>  	uint32_t id;
> -	uint32_t type;
> -	uint32_t count;
> +	uint8_t type;
> +	uint8_t is_array;
> +	uint16_t count;
>  	uint32_t offset;
> +	uint32_t padding[1];

Why the [1]? Do you plan to increase to provide extra padding?
If so why not do it now?

Otherwise uint32_t padding would be sufficient right ?


>  };
>  
>  struct ipa_control_range_entry {
> diff --git a/src/libcamera/ipa_controls.cpp b/src/libcamera/ipa_controls.cpp
> index 25f38bab3dd9..cfb5c59dd028 100644
> --- a/src/libcamera/ipa_controls.cpp
> +++ b/src/libcamera/ipa_controls.cpp
> @@ -163,11 +163,15 @@ static_assert(sizeof(ipa_controls_header) == 32,
>   * The numerical ID of the control
>   * \var ipa_control_value_entry::type
>   * The type of the control (defined by enum ControlType)
> + * \var ipa_control_value_entry::is_array
> + * True if the control value stores an array, false otherwise
>   * \var ipa_control_value_entry::count

Shouldn't count move to match the ordering in the struct?

>   * The number of control array entries for array controls (1 otherwise)
>   * \var ipa_control_value_entry::offset
>   * The offset in bytes from the beginning of the data section to the control
>   * value data (shall be a multiple of 8 bytes).
> + * \var ipa_control_value_entry::padding
> + * Padding bytes (shall be set to 0)
>   */
>  
>  static_assert(sizeof(ipa_control_value_entry) == 16,
> 

-- 
Regards
--
Kieran