[PATCH 06/11] media: Trace the stateless controls when set in v4l2-ctrls-core.c

Detlev Casanova
2026-02-12T16:24:13Z

Also remove the trace from visl as the generic v4l2-requests traces can
now be used instead.

It allows all stateless drivers to inherit traceability, with just a small
overhead when disabled in userspace.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
drivers/media/test-drivers/visl/visl-dec.c | 74 -------------
drivers/media/v4l2-core/v4l2-ctrls-api.c | 10 ++
drivers/media/v4l2-core/v4l2-ctrls-core.c | 114 +++++++++++++++++++++
include/media/v4l2-ctrls.h | 15 +++
4 files changed, 139 insertions(+), 74 deletions(-)

diff --git a/drivers/media/test-drivers/visl/visl-dec.c b/drivers/media/test-drivers/visl/visl-dec.c
index fc216da17048..9517830fb3e8 100644
--- a/drivers/media/test-drivers/visl/visl-dec.c
+++ b/drivers/media/test-drivers/visl/visl-dec.c
@@ -12,7 +12,6 @@
#include <linux/workqueue.h>
#include <media/v4l2-mem2mem.h>
#include <media/tpg/v4l2-tpg.h>
-#include <trace/events/v4l2_requests.h>

#define LAST_BUF_IDX (V4L2_AV1_REF_LAST_FRAME - V4L2_AV1_REF_LAST_FRAME)
#define LAST2_BUF_IDX (V4L2_AV1_REF_LAST2_FRAME - V4L2_AV1_REF_LAST_FRAME)
@@ -486,78 +485,6 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct visl_run *run)
}
}

-static void visl_trace_ctrls(struct visl_ctx *ctx, struct visl_run *run)
-{
- int i;
- struct v4l2_fh *fh = &ctx->fh;
-
- switch (ctx->current_codec) {
- default:
- case VISL_CODEC_NONE:
- break;
- case VISL_CODEC_FWHT:
- trace_v4l2_ctrl_fwht_params(fh->tgid, fh->fd, run->fwht.params);
- break;
- case VISL_CODEC_MPEG2:
- trace_v4l2_ctrl_mpeg2_sequence(fh->tgid, fh->fd, run->mpeg2.seq);
- trace_v4l2_ctrl_mpeg2_picture(fh->tgid, fh->fd, run->mpeg2.pic);
- trace_v4l2_ctrl_mpeg2_quantisation(fh->tgid, fh->fd, run->mpeg2.quant);
- break;
- case VISL_CODEC_VP8:
- trace_v4l2_ctrl_vp8_frame(fh->tgid, fh->fd, run->vp8.frame);
- trace_v4l2_ctrl_vp8_entropy(fh->tgid, fh->fd, run->vp8.frame);
- break;
- case VISL_CODEC_VP9:
- trace_v4l2_ctrl_vp9_frame(fh->tgid, fh->fd, run->vp9.frame);
- trace_v4l2_ctrl_vp9_compressed_hdr(fh->tgid, fh->fd, run->vp9.probs);
- trace_v4l2_ctrl_vp9_compressed_coeff(fh->tgid, fh->fd, run->vp9.probs);
- trace_v4l2_vp9_mv_probs(fh->tgid, fh->fd, &run->vp9.probs->mv);
- break;
- case VISL_CODEC_H264:
- trace_v4l2_ctrl_h264_sps(fh->tgid, fh->fd, run->h264.sps);
- trace_v4l2_ctrl_h264_pps(fh->tgid, fh->fd, run->h264.pps);
- trace_v4l2_ctrl_h264_scaling_matrix(fh->tgid, fh->fd, run->h264.sm);
- trace_v4l2_ctrl_h264_slice_params(fh->tgid, fh->fd, run->h264.spram);
-
- for (i = 0; i < ARRAY_SIZE(run->h264.spram->ref_pic_list0); i++)
- trace_v4l2_h264_ref_pic_list0(fh->tgid, fh->fd,
- &run->h264.spram->ref_pic_list0[i], i);
- for (i = 0; i < ARRAY_SIZE(run->h264.spram->ref_pic_list0); i++)
- trace_v4l2_h264_ref_pic_list1(fh->tgid, fh->fd,
- &run->h264.spram->ref_pic_list1[i], i);
-
- trace_v4l2_ctrl_h264_decode_params(fh->tgid, fh->fd, run->h264.dpram);
-
- for (i = 0; i < ARRAY_SIZE(run->h264.dpram->dpb); i++)
- trace_v4l2_h264_dpb_entry(fh->tgid, fh->fd, &run->h264.dpram->dpb[i], i);
-
- trace_v4l2_ctrl_h264_pred_weights(fh->tgid, fh->fd, run->h264.pwht);
- break;
- case VISL_CODEC_HEVC:
- trace_v4l2_ctrl_hevc_sps(fh->tgid, fh->fd, run->hevc.sps);
- trace_v4l2_ctrl_hevc_pps(fh->tgid, fh->fd, run->hevc.pps);
- trace_v4l2_ctrl_hevc_slice_params(fh->tgid, fh->fd, run->hevc.spram);
- trace_v4l2_ctrl_hevc_scaling_matrix(fh->tgid, fh->fd, run->hevc.sm);
- trace_v4l2_ctrl_hevc_decode_params(fh->tgid, fh->fd, run->hevc.dpram);
-
- for (i = 0; i < ARRAY_SIZE(run->hevc.dpram->dpb); i++)
- trace_v4l2_hevc_dpb_entry(fh->tgid, fh->fd, &run->hevc.dpram->dpb[i]);
-
-
- trace_v4l2_hevc_pred_weight_table(fh->tgid, fh->fd,
- &run->hevc.spram->pred_weight_table);
- trace_v4l2_ctrl_hevc_ext_sps_lt_rps(fh->tgid, fh->fd, run->hevc.rps_lt);
- trace_v4l2_ctrl_hevc_ext_sps_st_rps(fh->tgid, fh->fd, run->hevc.rps_st);
- break;
- case VISL_CODEC_AV1:
- trace_v4l2_ctrl_av1_sequence(fh->tgid, fh->fd, run->av1.seq);
- trace_v4l2_ctrl_av1_frame(fh->tgid, fh->fd, run->av1.frame);
- trace_v4l2_ctrl_av1_film_grain(fh->tgid, fh->fd, run->av1.grain);
- trace_v4l2_ctrl_av1_tile_group_entry(fh->tgid, fh->fd, run->av1.tge);
- break;
- }
-}
-
void visl_device_run(void *priv)
{
struct visl_ctx *ctx = priv;
@@ -634,7 +561,6 @@ void visl_device_run(void *priv)
run.dst->sequence, run.dst->vb2_buf.timestamp);

visl_tpg_fill(ctx, &run);
- visl_trace_ctrls(ctx, &run);

if (bitstream_trace_frame_start > -1 &&
run.dst->sequence >= bitstream_trace_frame_start &&
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c
index 0078a04c5445..8a814eec7a30 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-api.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c
@@ -524,6 +524,12 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
}
EXPORT_SYMBOL(v4l2_g_ext_ctrls);

+static void trace_ext_ctrl(struct v4l2_fh *fh, const struct v4l2_ctrl *ctrl)
+{
+ if (ctrl->type_ops->trace)
+ ctrl->type_ops->trace(fh, ctrl, ctrl->p_cur);
+}
+
/* Validate a new control */
static int validate_new(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr p_new)
{
@@ -713,6 +719,10 @@ int try_set_ext_ctrls_common(struct v4l2_fh *fh,
idx = helpers[idx].next;
} while (!ret && idx);
}
+
+ if (set)
+ trace_ext_ctrl(fh, master);
+
v4l2_ctrl_unlock(master);
}

diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
index 79a157975f70..6165e36d8879 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
@@ -10,8 +10,11 @@
#include <linux/slab.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
+#include <media/v4l2-fh.h>
#include <media/v4l2-fwnode.h>

+#include <trace/events/v4l2_requests.h>
+
#include "v4l2-ctrls-priv.h"

static const union v4l2_ctrl_ptr ptr_null;
@@ -1462,12 +1465,123 @@ int v4l2_ctrl_type_op_validate(const struct v4l2_ctrl *ctrl,
}
EXPORT_SYMBOL(v4l2_ctrl_type_op_validate);

+void v4l2_ctrl_type_op_trace(const struct v4l2_fh *fh,
+ const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr)
+{
+ int i = 0;
+
+ switch ((u32)ctrl->type) {
+ case V4L2_CTRL_TYPE_FWHT_PARAMS:
+ trace_v4l2_ctrl_fwht_params(fh->tgid, fh->fd, ptr.p_fwht_params);
+ break;
+ case V4L2_CTRL_TYPE_MPEG2_SEQUENCE:
+ trace_v4l2_ctrl_mpeg2_sequence(fh->tgid, fh->fd, ptr.p_mpeg2_sequence);
+ break;
+ case V4L2_CTRL_TYPE_MPEG2_PICTURE:
+ trace_v4l2_ctrl_mpeg2_picture(fh->tgid, fh->fd, ptr.p_mpeg2_picture);
+ break;
+ case V4L2_CTRL_TYPE_MPEG2_QUANTISATION:
+ trace_v4l2_ctrl_mpeg2_quantisation(fh->tgid, fh->fd, ptr.p_mpeg2_quantisation);
+ break;
+ case V4L2_CTRL_TYPE_VP8_FRAME:
+ trace_v4l2_ctrl_vp8_frame(fh->tgid, fh->fd, ptr.p_vp8_frame);
+ trace_v4l2_ctrl_vp8_entropy(fh->tgid, fh->fd, ptr.p_vp8_frame);
+ break;
+ case V4L2_CTRL_TYPE_VP9_FRAME:
+ trace_v4l2_ctrl_vp9_frame(fh->tgid, fh->fd, ptr.p_vp9_frame);
+ break;
+ case V4L2_CTRL_TYPE_VP9_COMPRESSED_HDR:
+ trace_v4l2_ctrl_vp9_compressed_hdr(fh->tgid, fh->fd,
+ ptr.p_vp9_compressed_hdr_probs);
+ trace_v4l2_ctrl_vp9_compressed_coeff(fh->tgid, fh->fd,
+ ptr.p_vp9_compressed_hdr_probs);
+ trace_v4l2_vp9_mv_probs(fh->tgid, fh->fd, &ptr.p_vp9_compressed_hdr_probs->mv);
+ break;
+ case V4L2_CTRL_TYPE_H264_SPS:
+ trace_v4l2_ctrl_h264_sps(fh->tgid, fh->fd, ptr.p_h264_sps);
+ break;
+ case V4L2_CTRL_TYPE_H264_PPS:
+ trace_v4l2_ctrl_h264_pps(fh->tgid, fh->fd, ptr.p_h264_pps);
+ break;
+ case V4L2_CTRL_TYPE_H264_SCALING_MATRIX:
+ trace_v4l2_ctrl_h264_scaling_matrix(fh->tgid, fh->fd, ptr.p_h264_scaling_matrix);
+ break;
+ case V4L2_CTRL_TYPE_H264_SLICE_PARAMS:
+ {
+ struct v4l2_ctrl_h264_slice_params *sp = ptr.p_h264_slice_params;
+
+ trace_v4l2_ctrl_h264_slice_params(fh->tgid, fh->fd, sp);
+
+ for (i = 0; i < ARRAY_SIZE(sp->ref_pic_list0); i++)
+ trace_v4l2_h264_ref_pic_list0(fh->tgid, fh->fd, &sp->ref_pic_list0[i], i);
+ for (i = 0; i < ARRAY_SIZE(sp->ref_pic_list1); i++)
+ trace_v4l2_h264_ref_pic_list1(fh->tgid, fh->fd, &sp->ref_pic_list1[i], i);
+
+ break;
+ }
+ case V4L2_CTRL_TYPE_H264_DECODE_PARAMS:
+ {
+ struct v4l2_ctrl_h264_decode_params *dp = ptr.p_h264_decode_params;
+
+ trace_v4l2_ctrl_h264_decode_params(fh->tgid, fh->fd, dp);
+
+ for (i = 0; i < ARRAY_SIZE(dp->dpb); i++)
+ trace_v4l2_h264_dpb_entry(fh->tgid, fh->fd, &dp->dpb[i], i);
+
+ break;
+ }
+ case V4L2_CTRL_TYPE_H264_PRED_WEIGHTS:
+ trace_v4l2_ctrl_h264_pred_weights(fh->tgid, fh->fd, ptr.p_h264_pred_weights);
+ break;
+ case V4L2_CTRL_TYPE_HEVC_SPS:
+ trace_v4l2_ctrl_hevc_sps(fh->tgid, fh->fd, ptr.p_hevc_sps);
+ break;
+ case V4L2_CTRL_TYPE_HEVC_PPS:
+ trace_v4l2_ctrl_hevc_pps(fh->tgid, fh->fd, ptr.p_hevc_pps);
+ break;
+ case V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS:
+ trace_v4l2_ctrl_hevc_slice_params(fh->tgid, fh->fd, ptr.p_hevc_slice_params);
+ trace_v4l2_hevc_pred_weight_table(fh->tgid, fh->fd,
+ &ptr.p_hevc_slice_params->pred_weight_table);
+ break;
+ case V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX:
+ trace_v4l2_ctrl_hevc_scaling_matrix(fh->tgid, fh->fd, ptr.p_hevc_scaling_matrix);
+ break;
+ case V4L2_CTRL_TYPE_HEVC_DECODE_PARAMS:
+ {
+ struct v4l2_ctrl_hevc_decode_params *dp = ptr.p_hevc_decode_params;
+
+ trace_v4l2_ctrl_hevc_decode_params(fh->tgid, fh->fd, dp);
+
+ for (i = 0; i < ARRAY_SIZE(dp->dpb); i++)
+ trace_v4l2_hevc_dpb_entry(fh->tgid, fh->fd, &dp->dpb[i]);
+
+ break;
+ }
+ case V4L2_CTRL_TYPE_AV1_SEQUENCE:
+ trace_v4l2_ctrl_av1_sequence(fh->tgid, fh->fd, ptr.p_av1_sequence);
+ break;
+ case V4L2_CTRL_TYPE_AV1_FRAME:
+ trace_v4l2_ctrl_av1_frame(fh->tgid, fh->fd, ptr.p_av1_frame);
+ break;
+ case V4L2_CTRL_TYPE_AV1_FILM_GRAIN:
+ trace_v4l2_ctrl_av1_film_grain(fh->tgid, fh->fd, ptr.p_av1_film_grain);
+ break;
+ case V4L2_CTRL_TYPE_AV1_TILE_GROUP_ENTRY:
+ trace_v4l2_ctrl_av1_tile_group_entry(fh->tgid, fh->fd, ptr.p_av1_tile_group_entry);
+ break;
+ }
+
+}
+EXPORT_SYMBOL(v4l2_ctrl_type_op_trace);
+
static const struct v4l2_ctrl_type_ops std_type_ops = {
.equal = v4l2_ctrl_type_op_equal,
.init = v4l2_ctrl_type_op_init,
.minimum = v4l2_ctrl_type_op_minimum,
.maximum = v4l2_ctrl_type_op_maximum,
.log = v4l2_ctrl_type_op_log,
+ .trace = v4l2_ctrl_type_op_trace,
.validate = v4l2_ctrl_type_op_validate,
};

diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index a2b4c96a9a6f..57c4bb999b7b 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -140,6 +140,7 @@ struct v4l2_ctrl_ops {
* @minimum: set the value to the minimum value of the control.
* @maximum: set the value to the maximum value of the control.
* @log: log the value.
+ * @trace: trace the value of the control with Ftrace.
* @validate: validate the value for ctrl->new_elems array elements.
* Return 0 on success and a negative value otherwise.
*/
@@ -153,6 +154,8 @@ struct v4l2_ctrl_type_ops {
void (*maximum)(const struct v4l2_ctrl *ctrl, u32 idx,
union v4l2_ctrl_ptr ptr);
void (*log)(const struct v4l2_ctrl *ctrl);
+ void (*trace)(const struct v4l2_fh *fh,
+ const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
int (*validate)(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
};

@@ -1627,6 +1630,18 @@ void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
*/
void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl);

+/**
+ * v4l2_ctrl_type_op_trace - Default v4l2_ctrl_type_ops trace callback.
+ *
+ * @fh: The v4l2_fh of the current context.
+ * @ctrl: The v4l2_ctrl pointer.
+ * @ptr: The v4l2 control value.
+ *
+ * Return: void
+ */
+void v4l2_ctrl_type_op_trace(const struct v4l2_fh *fh,
+ const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
+
/**
* v4l2_ctrl_type_op_validate - Default v4l2_ctrl_type_ops validate callback.
*
--
2.53.0