[{"id":38737,"web_url":"https://patchwork.libcamera.org/comment/38737/","msgid":"<177805532806.3225262.9758030782686157851@ping.linuxembedded.co.uk>","date":"2026-05-06T08:15:28","subject":"Re: [PATCH 1/3] include: v4l2-isp: Update to support extensible\n\tstats","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Jacopo Mondi (2026-05-05 17:11:09)\n> Update the v4l2-isp.h header to prepare to support extensible\n> statistics.\n> \n> The new header version is generated from the following in-review\n> patch series:\n> https://patchwork.linuxtv.org/project/linux-media/patch/20260505-extensible-stats-v1-1-e16f326b8dad@ideasonboard.com/\n> \n> Signed-off-by: Jacopo Mondi \n\nAcked-by: Kieran Bingham \n\n> ---\n> include/linux/media/v4l2-isp.h | 125 ++++++++++++++++++++++++++---------------\n> 1 file changed, 79 insertions(+), 46 deletions(-)\n> \n> diff --git a/include/linux/media/v4l2-isp.h b/include/linux/media/v4l2-isp.h\n> index 0cfc4ab94967..60a716177d52 100644\n> --- a/include/linux/media/v4l2-isp.h\n> +++ b/include/linux/media/v4l2-isp.h\n> @@ -13,25 +13,33 @@\n> #include \n> \n> /**\n> - * enum v4l2_isp_params_version - V4L2 ISP parameters versioning\n> + * enum v4l2_isp_version - V4L2 ISP serialization format versioning\n> *\n> - * @V4L2_ISP_PARAMS_VERSION_V0: First version of the V4L2 ISP parameters format\n> - * (for compatibility)\n> - * @V4L2_ISP_PARAMS_VERSION_V1: First version of the V4L2 ISP parameters format\n> + * @V4L2_ISP_VERSION_V0: First version of the V4L2 ISP serialization format\n> + * (for compatibility)\n> + * @V4L2_ISP_VERSION_V1: First version of the V4L2 ISP serialization format\n> *\n> * V0 and V1 are identical in order to support drivers compatible with the V4L2\n> - * ISP parameters format already upstreamed which use either 0 or 1 as their\n> - * versioning identifier. Both V0 and V1 refers to the first version of the\n> - * V4L2 ISP parameters format.\n> + * ISP format already upstreamed which use either 0 or 1 as their versioning\n> + * identifier. Both V0 and V1 refers to the first version of the V4L2 ISP\n> + * serialization format.\n> *\n> - * Future revisions of the V4L2 ISP parameters format should start from the\n> + * Future revisions of the V4L2 ISP serialization format should start from the\n> * value of 2.\n> */\n> -enum v4l2_isp_params_version {\n> - V4L2_ISP_PARAMS_VERSION_V0 = 0,\n> - V4L2_ISP_PARAMS_VERSION_V1\n> +enum v4l2_isp_version {\n> + V4L2_ISP_VERSION_V0 = 0,\n> + V4L2_ISP_VERSION_V1\n> };\n> \n> +/*\n> + * Compatibility with existing users of v4l2_isp_params which pre-date the\n> + * introduction of v4l2_isp_stats.\n> + */\n> +#define v4l2_isp_params_version v4l2_isp_version\n> +#define V4L2_ISP_PARAMS_VERSION_V0 V4L2_ISP_VERSION_V0\n> +#define V4L2_ISP_PARAMS_VERSION_V1 V4L2_ISP_VERSION_V1\n> +\n> #define V4L2_ISP_PARAMS_FL_BLOCK_DISABLE (1U << 0)\n> #define V4L2_ISP_PARAMS_FL_BLOCK_ENABLE (1U << 1)\n> \n> @@ -39,64 +47,89 @@ enum v4l2_isp_params_version {\n> * Reserve the first 8 bits for V4L2_ISP_PARAMS_FL_* flag.\n> *\n> * Driver-specific flags should be defined as:\n> - * #define DRIVER_SPECIFIC_FLAG0 ((1U << V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(0))\n> - * #define DRIVER_SPECIFIC_FLAG1 ((1U << V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(1))\n> + * #define DRIVER_SPECIFIC_FLAG0 ((1U << V4L2_ISP_FL_DRIVER_FLAGS(0))\n> + * #define DRIVER_SPECIFIC_FLAG1 ((1U << V4L2_ISP_FL_DRIVER_FLAGS(1))\n> */\n> -#define V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(n) ((n) + 8)\n> +#define V4L2_ISP_FL_DRIVER_FLAGS(n) ((n) + 8)\n> \n> /**\n> - * struct v4l2_isp_params_block_header - V4L2 extensible parameters block header\n> - * @type: The parameters block type (driver-specific)\n> + * struct v4l2_isp_block_header - V4L2 extensible block header\n> + * @type: The parameters or statistics block type (driver-specific)\n> * @flags: A bitmask of block flags (driver-specific)\n> - * @size: Size (in bytes) of the parameters block, including this header\n> + * @size: Size (in bytes) of the block, including this header\n> *\n> - * This structure represents the common part of all the ISP configuration\n> - * blocks. Each parameters block shall embed an instance of this structure type\n> - * as its first member, followed by the block-specific configuration data.\n> + * This structure represents the common part of all the ISP configuration or\n> + * statistic blocks. Each block shall embed an instance of this structure type\n> + * as its first member, followed by the block-specific configuration or\n> + * statistic data.\n> *\n> * The @type field is an ISP driver-specific value that identifies the block\n> - * type. The @size field specifies the size of the parameters block.\n> + * type. The @size field specifies the size of the block, including this\n> + * header.\n> *\n> - * The @flags field is a bitmask of per-block flags V4L2_PARAMS_ISP_FL_* and\n> - * driver-specific flags specified by the driver header.\n> + * The @flags field is a bitmask of per-block flags. If a block is used for\n> + * configuration parameters this field can be a combination of\n> + * V4L2_ISP_PARAMS_FL_* and driver-specific flags. If a block is used\n> + * for statistics this fields is used to report optional\n> + * driver-specific flags, if any.\n> */\n> -struct v4l2_isp_params_block_header {\n> +struct v4l2_isp_block_header {\n> __u16 type;\n> __u16 flags;\n> __u32 size;\n> } __attribute__((aligned(8)));\n> \n> /**\n> - * struct v4l2_isp_params_buffer - V4L2 extensible parameters configuration\n> - * @version: The parameters buffer version (driver-specific)\n> - * @data_size: The configuration data effective size, excluding this header\n> - * @data: The configuration data\n> + * v4l2_isp_params_block_header - V4L2 extensible parameters block header\n> + *\n> + * Compatibility with existing users of v4l2_isp_params_block_header\n> + * which pre-date the introduction of v4l2_isp_block_header.\n> + */\n> +#define v4l2_isp_params_block_header v4l2_isp_block_header\n> +\n> +/**\n> + * struct v4l2_isp_buffer - V4L2 extensible buffer\n> + * @version: The extensible buffer version (driver-specific)\n> + * @data_size: The data effective size, excluding this header\n> + * @data: The configuration or statistics data\n> *\n> - * This structure contains the configuration parameters of the ISP algorithms,\n> - * serialized by userspace into a data buffer. Each configuration parameter\n> - * block is represented by a block-specific structure which contains a\n> - * :c:type:`v4l2_isp_params_block_header` entry as first member. Userspace\n> - * populates the @data buffer with configuration parameters for the blocks that\n> - * it intends to configure. As a consequence, the data buffer effective size\n> - * changes according to the number of ISP blocks that userspace intends to\n> - * configure and is set by userspace in the @data_size field.\n> + * This structure contains ISP configuration parameters or ISP hardware\n> + * statistics serialized into a data buffer. Each block is represented by a\n> + * block-specific structure which contains a :c:type:`v4l2_isp_block_header`\n> + * entry as first member.\n> *\n> - * The parameters buffer is versioned by the @version field to allow modifying\n> - * and extending its definition. Userspace shall populate the @version field to\n> - * inform the driver about the version it intends to use. The driver will parse\n> - * and handle the @data buffer according to the data layout specific to the\n> - * indicated version and return an error if the desired version is not\n> + * When used for ISP parameters, userspace populates the @data buffer with\n> + * configuration parameters for the blocks that it intends to configure. As a\n> + * consequence, the data buffer effective size changes according to the number\n> + * of ISP blocks that userspace intends to configure.\n> + *\n> + * When used to report ISP statistics, the driver populates the @data buffer\n> + * with statistics for each supported measurement block.\n> + *\n> + * The buffer is versioned by the @version field to allow modifying\n> + * and extending its definition. The writer shall populate the @version field\n> + * to inform the reader about the version it intends to use. The reader will\n> + * parse and handle the @data buffer according to the data layout specific to\n> + * the indicated version and return an error if the desired version is not\n> * supported.\n> *\n> - * For each ISP block that userspace wants to configure, a block-specific\n> - * structure is appended to the @data buffer, one after the other without gaps\n> - * in between. Userspace shall populate the @data_size field with the effective\n> - * size, in bytes, of the @data buffer.\n> + * For each ISP block, a block-specific structure is appended to the @data\n> + * buffer, one after the other without gaps in between. The writer shall\n> + * populate the @data_size field with the effective size, in bytes, of the\n> + * @data buffer.\n> */\n> -struct v4l2_isp_params_buffer {\n> +struct v4l2_isp_buffer {\n> __u32 version;\n> __u32 data_size;\n> __u8 data[] __counted_by(data_size);\n> };\n> \n> +/**\n> + * v4l2_isp_params_buffer - V4L2 extensible parameters compatibility\n> + *\n> + * Compatibility with existing users of v4l2_isp_params_buffer which\n> + * pre-date the introduction of v4l2_isp_buffer.\n> + */\n> +#define v4l2_isp_params_buffer v4l2_isp_buffer\n> +\n> #endif /* _V4L2_ISP_H_ */\n> \n> -- \n> 2.53.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 24FD1BDCB5\n\tfor ;\n\tWed, 6 May 2026 08:15:34 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 17B5163025;\n\tWed, 6 May 2026 10:15:33 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id AAD3462FE1\n\tfor ;\n\tWed, 6 May 2026 10:15:30 +0200 (CEST)","from monstersaurus.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 54324BE;\n\tWed, 6 May 2026 10:15:27 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"kquasSaV\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1778055327;\n\tbh=aWnVSRdb1xrY71VrIj1wzZAsBZrP7oDvCzrfE8cCQ+Q=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=kquasSaV12Qq/8qVEJL7nlx8oq/IcNzPG9sUEX1dJmQT7tzUg9LIn1GF3kooCngvJ\n\taC1H4rz9blUSEGrMWDXetuyTnWgVim4NrkNVmVqAhoBY9eeD3NZYs5bH7zBG4FRBB2\n\tJHvqMX1xVNKQrac3QuhARfRTGj2ESpiTfpIVpRp8=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20260505-extensible-stats-v1-1-0b56c7b1bbd6@ideasonboard.com>","References":"<20260505-extensible-stats-v1-0-0b56c7b1bbd6@ideasonboard.com>\n\t<20260505-extensible-stats-v1-1-0b56c7b1bbd6@ideasonboard.com>","Subject":"Re: [PATCH 1/3] include: v4l2-isp: Update to support extensible\n\tstats","From":"Kieran Bingham ","Cc":"Jacopo Mondi ","To":"Antoine Bouyer ,\n\tJacopo Mondi ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Wed, 06 May 2026 09:15:28 +0100","Message-ID":"<177805532806.3225262.9758030782686157851@ping.linuxembedded.co.uk>","User-Agent":"alot/0.9.1","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]