diff --git a/libavfilter/af_afade.c b/libavfilter/af_afade.c
index 4edfd27a3c..fc549522a3 100644
--- a/libavfilter/af_afade.c
+++ b/libavfilter/af_afade.c
@@ -555,9 +555,11 @@ static int activate(AVFilterContext *ctx)
             return ff_filter_frame(outlink, out);
         }
     } else if (ff_outlink_frame_wanted(ctx->outputs[0])) {
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (!s->cf0_eof && ff_outlink_get_status(ctx->inputs[0])) {
             s->cf0_eof = 1;
         }
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (ff_outlink_get_status(ctx->inputs[1])) {
             ff_outlink_set_status(ctx->outputs[0], AVERROR_EOF, AV_NOPTS_VALUE);
             return 0;
diff --git a/libavfilter/af_afir.c b/libavfilter/af_afir.c
index ca90a158a1..56725064b5 100644
--- a/libavfilter/af_afir.c
+++ b/libavfilter/af_afir.c
@@ -642,6 +642,7 @@ static int activate(AVFilterContext *ctx)
         if (ret < 0)
             return ret;
 
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (ff_outlink_get_status(ctx->inputs[1 + s->selir]) == AVERROR_EOF)
             s->eof_coeffs[s->selir] = 1;
 
@@ -698,6 +699,7 @@ static int activate(AVFilterContext *ctx)
     }
 
     if (ff_outlink_frame_wanted(ctx->outputs[0]) &&
+        /* FIXME calling ff_outlink_something on an input is invalid */
         !ff_outlink_get_status(ctx->inputs[0])) {
         ff_inlink_request_frame(ctx->inputs[0]);
         return 0;
@@ -705,6 +707,7 @@ static int activate(AVFilterContext *ctx)
 
     if (s->response &&
         ff_outlink_frame_wanted(ctx->outputs[1]) &&
+        /* FIXME calling ff_outlink_something on an input is invalid */
         !ff_outlink_get_status(ctx->inputs[0])) {
         ff_inlink_request_frame(ctx->inputs[0]);
         return 0;
diff --git a/libavfilter/af_headphone.c b/libavfilter/af_headphone.c
index edf8e773d7..317e631de5 100644
--- a/libavfilter/af_headphone.c
+++ b/libavfilter/af_headphone.c
@@ -520,6 +520,7 @@ static int activate(AVFilterContext *ctx)
             if ((ret = check_ir(input, i)) < 0)
                 return ret;
 
+            /* FIXME calling ff_outlink_something on an input is invalid */
             if (ff_outlink_get_status(input) == AVERROR_EOF) {
                 if (!ff_inlink_queued_samples(input)) {
                     av_log(ctx, AV_LOG_ERROR, "No samples provided for "
diff --git a/libavfilter/f_interleave.c b/libavfilter/f_interleave.c
index a18bbe79b3..638252f28e 100644
--- a/libavfilter/f_interleave.c
+++ b/libavfilter/f_interleave.c
@@ -116,10 +116,12 @@ static int activate(AVFilterContext *ctx)
     }
 
     for (i = 0; i < ctx->nb_inputs; i++)
+        /* FIXME calling ff_outlink_something on an input is invalid */
         nb_eofs += !!ff_outlink_get_status(ctx->inputs[i]);
 
     if ((nb_eofs > 0 && s->duration_mode == DURATION_SHORTEST) ||
         (nb_eofs == ctx->nb_inputs && s->duration_mode == DURATION_LONGEST) ||
+        /* FIXME calling ff_outlink_something on an input is invalid */
         (ff_outlink_get_status(ctx->inputs[0]) && s->duration_mode == DURATION_FIRST)) {
         ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
         return 0;
@@ -129,6 +131,7 @@ static int activate(AVFilterContext *ctx)
         if (ff_inlink_queued_frames(ctx->inputs[i]))
             continue;
         if (ff_outlink_frame_wanted(outlink) &&
+            /* FIXME calling ff_outlink_something on an input is invalid */
             !ff_outlink_get_status(ctx->inputs[i])) {
             ff_inlink_request_frame(ctx->inputs[i]);
             return 0;
diff --git a/libavfilter/vf_framepack.c b/libavfilter/vf_framepack.c
index b5d877ca99..e3f0b6b820 100644
--- a/libavfilter/vf_framepack.c
+++ b/libavfilter/vf_framepack.c
@@ -354,6 +354,7 @@ static int activate(AVFilterContext *ctx)
     FF_FILTER_FORWARD_STATUS(ctx->inputs[1], outlink);
 
     if (ff_outlink_frame_wanted(ctx->outputs[0]) &&
+        /* FIXME calling ff_outlink_something on an input is invalid */
         !ff_outlink_get_status(ctx->inputs[0]) &&
         !s->input_views[0]) {
         ff_inlink_request_frame(ctx->inputs[0]);
@@ -361,6 +362,7 @@ static int activate(AVFilterContext *ctx)
     }
 
     if (ff_outlink_frame_wanted(ctx->outputs[0]) &&
+        /* FIXME calling ff_outlink_something on an input is invalid */
         !ff_outlink_get_status(ctx->inputs[1]) &&
         !s->input_views[1]) {
         ff_inlink_request_frame(ctx->inputs[1]);
diff --git a/libavfilter/vf_xfade.c b/libavfilter/vf_xfade.c
index 7412709587..0eebfe457d 100644
--- a/libavfilter/vf_xfade.c
+++ b/libavfilter/vf_xfade.c
@@ -1824,10 +1824,12 @@ static int xfade_activate(AVFilterContext *ctx)
     }
 
     if (ff_outlink_frame_wanted(outlink)) {
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (!s->eof[0] && ff_outlink_get_status(ctx->inputs[0])) {
             s->eof[0] = 1;
             s->xfade_is_over = 1;
         }
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (!s->eof[1] && ff_outlink_get_status(ctx->inputs[1])) {
             s->eof[1] = 1;
         }
diff --git a/libavfilter/vf_xfade_opencl.c b/libavfilter/vf_xfade_opencl.c
index 4736043147..18f0ce29d8 100644
--- a/libavfilter/vf_xfade_opencl.c
+++ b/libavfilter/vf_xfade_opencl.c
@@ -323,10 +323,12 @@ static int xfade_opencl_activate(AVFilterContext *avctx)
     }
 
     if (ff_outlink_frame_wanted(outlink)) {
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (!ctx->eof[0] && ff_outlink_get_status(avctx->inputs[0])) {
             ctx->eof[0] = 1;
             ctx->xfade_is_over = 1;
         }
+        /* FIXME calling ff_outlink_something on an input is invalid */
         if (!ctx->eof[1] && ff_outlink_get_status(avctx->inputs[1])) {
             ctx->eof[1] = 1;
         }
