[PATCH v0 3/4] media: chips-media: wave5: avoid skipping device_run while VPU has work

[Jackson.lee]

From: Jackson Lee <jackson.lee@xxxxxxxxxxxxxxx>

The decoder stalls because empty_queue is set to true even when the
m2m context still has pending commands. As a result, device_run is
never invoked, the m2m source queue fills up, and userspace (e.g.
Chromium) can no longer queue new bitstream buffers to the V4L2
driver.

Fix this by querying the VPU queue status via DEC_GET_QUEUE_STATUS
before deciding whether to skip device_run. Only skip when the
VPU's instance_queue_count equals the number of ready source
buffers in the v4l2-m2m context, which indicates that there is
genuinely no new work to perform. Otherwise, proceed with issuing
a decode command so that the VPU can continue draining its internal
queue.

Fixes: a176ac5e701f ("media: chips-media: wave5: Improve performance of decoder")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jackson Lee <jackson.lee@xxxxxxxxxxxxxxx>
Signed-off-by: Nas Chung <nas.chung@xxxxxxxxxxxxxxx>
---
 .../media/platform/chips-media/wave5/wave5-vpu-dec.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
index 01d1368b2965..b7fa19ea2aac 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
@@ -1663,9 +1663,15 @@ static void wave5_vpu_dec_device_run(void *priv)
 		} else if (!inst->eos &&
 				inst->queuing_num == 0 &&
 				inst->state == VPU_INST_STATE_PIC_RUN) {
-			dev_dbg(inst->dev->dev, "%s: no bitstream for feeding, so skip ", __func__);
-			inst->empty_queue = true;
-			goto finish_job_and_return;
+			struct queue_status_info q_status;
+
+			wave5_vpu_dec_give_command(inst, DEC_GET_QUEUE_STATUS, &q_status);
+			if (q_status.instance_queue_count == v4l2_m2m_num_src_bufs_ready(m2m_ctx)) {
+				dev_dbg(inst->dev->dev, "%s: no bitstream, skip\n",
+					__func__);
+				inst->empty_queue = true;
+				goto finish_job_and_return;
+			}
 		}
 	}
 
-- 
2.43.0