[PATCH] media: i2c: vd55g1: Fix wrong output FPS value

[Benjamin Mugnier]

Running the sensor on 10 bits mode resulted in FPS being 25% faster than
it should be. This issue did not appear in 8 bits mode. This is mostly
noticeable with libcamera as it can set a target FPS value directly.

This is caused by the V4L2_CID_PIXEL_RATE control being dynamically
changed according to the media bus code, while it should be the same
regardless of the code.

Since we already compute the pixel_clock, use it directly for
V4L2_CID_PIXEL_RATE instead.

Suggested-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
Signed-off-by: Benjamin Mugnier <benjamin.mugnier@xxxxxxxxxxx>
---
 drivers/media/i2c/vd55g1.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/drivers/media/i2c/vd55g1.c b/drivers/media/i2c/vd55g1.c
index 78d18c028154..bb11394ed3e5 100644
--- a/drivers/media/i2c/vd55g1.c
+++ b/drivers/media/i2c/vd55g1.c
@@ -649,12 +649,6 @@ static u32 vd55g1_get_fmt_code(struct vd55g1 *sensor, u32 code)
 	return vd55g1_mbus_formats_bayer[i][j];
 }
 
-static s32 vd55g1_get_pixel_rate(struct vd55g1 *sensor,
-				 struct v4l2_mbus_framefmt *format)
-{
-	return sensor->mipi_rate / vd55g1_get_fmt_bpp(format->code);
-}
-
 static unsigned int vd55g1_get_hblank_min(struct vd55g1 *sensor,
 					  struct v4l2_mbus_framefmt *format,
 					  struct v4l2_rect *crop)
@@ -1285,12 +1279,6 @@ static int vd55g1_new_format_change_controls(struct vd55g1 *sensor,
 	if (ret)
 		return ret;
 
-	/* Update pixel rate to reflect new bpp */
-	ret = __v4l2_ctrl_s_ctrl_int64(sensor->pixel_rate_ctrl,
-				       vd55g1_get_pixel_rate(sensor, format));
-	if (ret)
-		return ret;
-
 	/* Update hblank according to new width */
 	hblank = vd55g1_get_hblank_min(sensor, format, crop);
 	ret = __v4l2_ctrl_modify_range(sensor->hblank_ctrl, hblank, hblank, 1,
@@ -1549,7 +1537,6 @@ static int vd55g1_init_ctrls(struct vd55g1 *sensor)
 		v4l2_subdev_state_get_crop(state, 0);
 	struct v4l2_mbus_framefmt *format =
 		v4l2_subdev_state_get_format(state, 0);
-	s32 pixel_rate = vd55g1_get_pixel_rate(sensor, format);
 	int ret;
 
 	v4l2_ctrl_handler_init(hdl, 16);
@@ -1591,7 +1578,7 @@ static int vd55g1_init_ctrls(struct vd55g1 *sensor)
 	sensor->pixel_rate_ctrl = v4l2_ctrl_new_std(hdl, ops,
 						    V4L2_CID_PIXEL_RATE, 1,
 						    INT_MAX, 1,
-						    pixel_rate);
+						    sensor->pixel_clock);
 	if (sensor->pixel_rate_ctrl)
 		sensor->pixel_rate_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 	sensor->ae_lock_ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_3A_LOCK,

---
base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
change-id: 20260701-fix_vd55g1_fps-d3d4b00d7630

Best regards,
--  
Benjamin Mugnier <benjamin.mugnier@xxxxxxxxxxx>