[RFC PATCH v2 3/4] media: iris: Signal V4L2_EVENT_EOS only at the end of a drain

[Christian Cortner <ccortner@gmail.com>]

V4L2_EVENT_EOS is queued, and the m2m context marked stopped, for every
LAST capture buffer, including the one that ends a source change. With
a stream that changes resolution, a client gets EOS at the change and
none at the end, and ffmpeg's h264_v4l2m2m stops decoding there.

Do both only when IRIS_INST_SUB_DRAIN_LAST is set, which both HFI
generations do before they return the LAST buffer of a drain. Use one
helper for iris_vb2_buffer_done() and iris_vb2_buf_queue().

Fixes: 84e17adae3e3 ("media: iris: add support for dynamic resolution change")
Cc: stable@vger.kernel.org
Assisted-by: LLM sparse smatch
---
 .../media/platform/qcom/iris/iris_buffer.c    | 26 ++++++++++++++-----
 .../media/platform/qcom/iris/iris_buffer.h    |  1 +
 drivers/media/platform/qcom/iris/iris_vb2.c   |  6 +----
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/media/platform/qcom/iris/iris_buffer.c b/drivers/media/platform/qcom/iris/iris_buffer.c
index eb8de60c1177..178e50eadcf7 100644
--- a/drivers/media/platform/qcom/iris/iris_buffer.c
+++ b/drivers/media/platform/qcom/iris/iris_buffer.c
@@ -870,9 +870,26 @@ static void iris_get_ts_metadata(struct iris_inst *inst, u64 timestamp_ns,
 	vbuf->timecode = inst->tss[inst->metadata_idx].tc;
 }
 
-int iris_vb2_buffer_done(struct iris_inst *inst, struct iris_buffer *buf)
+/*
+ * Queue V4L2_EVENT_EOS and mark the m2m context stopped, once, when a LAST
+ * capture buffer ends a drain. The LAST buffer of a source change does not
+ * end the stream.
+ */
+void iris_vb2_signal_eos(struct iris_inst *inst)
 {
+	static const struct v4l2_event eos = { .type = V4L2_EVENT_EOS };
 	struct v4l2_m2m_ctx *m2m_ctx = inst->m2m_ctx;
+
+	if (!(inst->sub_state & IRIS_INST_SUB_DRAIN_LAST) ||
+	    v4l2_m2m_has_stopped(m2m_ctx))
+		return;
+
+	v4l2_event_queue_fh(&inst->fh, &eos);
+	v4l2_m2m_mark_stopped(m2m_ctx);
+}
+
+int iris_vb2_buffer_done(struct iris_inst *inst, struct iris_buffer *buf)
+{
 	struct vb2_v4l2_buffer *vbuf;
 	struct vb2_buffer *vb2;
 	u32 type, state;
@@ -913,12 +930,7 @@ int iris_vb2_buffer_done(struct iris_inst *inst, struct iris_buffer *buf)
 	}
 
 	if (vbuf->flags & V4L2_BUF_FLAG_LAST) {
-		if (!v4l2_m2m_has_stopped(m2m_ctx)) {
-			const struct v4l2_event ev = { .type = V4L2_EVENT_EOS };
-
-			v4l2_event_queue_fh(&inst->fh, &ev);
-			v4l2_m2m_mark_stopped(m2m_ctx);
-		}
+		iris_vb2_signal_eos(inst);
 		inst->last_buffer_dequeued = true;
 	}
 
diff --git a/drivers/media/platform/qcom/iris/iris_buffer.h b/drivers/media/platform/qcom/iris/iris_buffer.h
index ab8e5d953101..a8d2002e00ee 100644
--- a/drivers/media/platform/qcom/iris/iris_buffer.h
+++ b/drivers/media/platform/qcom/iris/iris_buffer.h
@@ -120,6 +120,7 @@ int iris_alloc_and_queue_input_int_bufs(struct iris_inst *inst);
 int iris_queue_buffer(struct iris_inst *inst, struct iris_buffer *buf);
 int iris_queue_deferred_buffers(struct iris_inst *inst, enum iris_buffer_type buf_type);
 int iris_vb2_buffer_done(struct iris_inst *inst, struct iris_buffer *buf);
+void iris_vb2_signal_eos(struct iris_inst *inst);
 void iris_vb2_queue_error(struct iris_inst *inst);
 
 #endif
diff --git a/drivers/media/platform/qcom/iris/iris_vb2.c b/drivers/media/platform/qcom/iris/iris_vb2.c
index 8faf709c26c1..bb713da20605 100644
--- a/drivers/media/platform/qcom/iris/iris_vb2.c
+++ b/drivers/media/platform/qcom/iris/iris_vb2.c
@@ -290,7 +290,6 @@ int iris_vb2_buf_out_validate(struct vb2_buffer *vb)
 
 void iris_vb2_buf_queue(struct vb2_buffer *vb2)
 {
-	static const struct v4l2_event eos = { .type = V4L2_EVENT_EOS };
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb2);
 	struct v4l2_m2m_ctx *m2m_ctx;
 	struct iris_inst *inst;
@@ -324,10 +323,7 @@ void iris_vb2_buf_queue(struct vb2_buffer *vb2)
 			vbuf->field = V4L2_FIELD_NONE;
 			vb2_set_plane_payload(vb2, 0, 0);
 			v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_DONE);
-			if (!v4l2_m2m_has_stopped(m2m_ctx)) {
-				v4l2_event_queue_fh(&inst->fh, &eos);
-				v4l2_m2m_mark_stopped(m2m_ctx);
-			}
+			iris_vb2_signal_eos(inst);
 			inst->last_buffer_dequeued = true;
 			goto exit;
 		}
-- 
2.56.0