media: iris: Send V4L2_BUF_FLAG_ERROR for capture buffers with 0 filled length

commit 7adc11e upstream.

Firmware sends capture buffers with 0 filled length which are not to be
displayed and should be dropped by client.
To achieve the same, add V4L2_BUF_FLAG_ERROR to such buffers by making
sure:
- These 0 length buffers are not returned as result of flush.
- Its not a buffer with LAST flag enabled which will also have 0 filled
  length.

Cc: stable@vger.kernel.org
Fixes: d091007 ("media: iris: add support for drain sequence")
Acked-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-HDK
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Tested-by: Vikash Garodia <quic_vgarodia@quicinc.com> # on sa8775p-ride
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Dikshita Agarwal

drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c

@@ -378,6 +378,11 @@ static int iris_hfi_gen2_handle_output_buffer(struct iris_inst *inst,
 
 	buf->flags = iris_hfi_gen2_get_driver_buffer_flags(inst, hfi_buffer->flags);
 
+	if (!buf->data_size && inst->state == IRIS_INST_STREAMING &&
+	    !(hfi_buffer->flags & HFI_BUF_FW_FLAG_LAST)) {
+		buf->flags |= V4L2_BUF_FLAG_ERROR;
+	}
+
 	return 0;
 }