Re: [PATCH 12/21] media: ov5640: Fix durations to comply with FPS

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

Thank you for the patch.

On Mon, Jan 31, 2022 at 03:44:40PM +0100, Jacopo Mondi wrote:
> Now that the frame duration can be controlled by tuning the VBLANK
> duration, fix all modes to comply with the reported FPS.
> 
> All modes run at 30 FPS except for full-resolution mode 2592x1944
> which runs at 15FPS.
> 
> Tested on a 2 data lanes setup in UYVY and RGB565 modes.
> 
> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> ---
>  drivers/media/i2c/ov5640.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 6eeb50724195..2176fa0b8eae 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -611,8 +611,8 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.width	= 160,
>  			.height	= 120,
>  		},
> -		.ppl		= 1896,
> -		.vblank_def	= 864,
> +		.ppl		= 1600,
> +		.vblank_def	= 878,

The total number of pixels is changed from 1896 * (120+864) = 1865664 to
1600 * (120+878) = 1596800. The latter produces 30.06fps with a 48 Mp/s
rate, which certainly seems better than the 25.73fps produced by the
format. I wonder, though, if this has always been wrong, or if the
incorrect frame rate got introduced earlier in this series.

Also, how did you pick a htot value of 1600 ?

>  		.reg_data	= ov5640_setting_QQVGA_160_120,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_QQVGA_160_120),
>  		.max_fps	= OV5640_30_FPS
> @@ -633,8 +633,8 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.width	= 176,
>  			.height	= 144,
>  		},
> -		.ppl		= 1896,
> -		.vblank_def	= 840,
> +		.ppl		= 1600,
> +		.vblank_def	= 854,
>  		.reg_data	= ov5640_setting_QCIF_176_144,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_QCIF_176_144),
>  		.max_fps	= OV5640_30_FPS
> @@ -655,8 +655,8 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.width	= 320,
>  			.height	= 240,
>  		},
> -		.ppl		= 1896,
> -		.vblank_def	= 744,
> +		.ppl		= 1600,
> +		.vblank_def	= 760,
>  		.reg_data	= ov5640_setting_QVGA_320_240,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_QVGA_320_240),
>  		.max_fps	= OV5640_30_FPS
> @@ -677,8 +677,8 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.width	= 640,
>  			.height	= 480,
>  		},
> -		.ppl		= 1896,
> -		.vblank_def	= 600,
> +		.ppl		= 1600,
> +		.vblank_def	= 520,
>  		.reg_data	= ov5640_setting_VGA_640_480,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_VGA_640_480),
>  		.max_fps	= OV5640_60_FPS
> @@ -700,7 +700,7 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.height	= 480,
>  		},
>  		.ppl		= 1896,
> -		.vblank_def	= 504,
> +		.vblank_def	= 1206,
>  		.reg_data	= ov5640_setting_NTSC_720_480,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_NTSC_720_480),
>  		.max_fps	= OV5640_30_FPS
> @@ -722,7 +722,7 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.height	= 576,
>  		},
>  		.ppl		= 1896,
> -		.vblank_def	= 408,
> +		.vblank_def	= 1110,
>  		.reg_data	= ov5640_setting_PAL_720_576,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_PAL_720_576),
>  		.max_fps	= OV5640_30_FPS
> @@ -744,7 +744,7 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.height	= 768,
>  		},
>  		.ppl		= 1896,
> -		.vblank_def	= 312,
> +		.vblank_def	= 918,
>  		.reg_data	= ov5640_setting_XGA_1024_768,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_XGA_1024_768),
>  		.max_fps	= OV5640_30_FPS
> @@ -765,8 +765,8 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.width	= 1280,
>  			.height	= 720,
>  		},
> -		.ppl		= 1896,
> -		.vblank_def	= 20,
> +		.ppl		= 1600,
> +		.vblank_def	= 560,
>  		.reg_data	= ov5640_setting_720P_1280_720,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_720P_1280_720),
>  		.max_fps	= OV5640_30_FPS
> @@ -787,8 +787,8 @@ ov5640_mode_data[OV5640_NUM_MODES] = {
>  			.width	= 1920,
>  			.height	= 1080,
>  		},
> -		.ppl		= 2500,
> -		.vblank_def	= 40,
> +		.ppl		= 2234,
> +		.vblank_def	= 24,
>  		.reg_data	= ov5640_setting_1080P_1920_1080,
>  		.reg_data_size	= ARRAY_SIZE(ov5640_setting_1080P_1920_1080),
>  		.max_fps	= OV5640_30_FPS

-- 
Regards,

Laurent Pinchart