diff --git a/modules/audio_remote_submix/audio_hw.cpp b/modules/audio_remote_submix/audio_hw.cpp
index f778693..dda0d0e 100644
--- a/modules/audio_remote_submix/audio_hw.cpp
+++ b/modules/audio_remote_submix/audio_hw.cpp
@@ -962,7 +962,7 @@
 {
     (void)stream;
     (void)timestamp;
-    return -EINVAL;
+    return -ENOSYS;
 }
 
 /** audio_stream_in implementation **/
@@ -1554,6 +1554,9 @@
         }
         const size_t frame_size_in_bytes = audio_channel_count_from_in_mask(config->channel_mask) *
                 audio_bytes_per_sample(config->format);
+        if (max_buffer_period_size_frames == 0) {
+            max_buffer_period_size_frames = DEFAULT_PIPE_SIZE_IN_FRAMES;
+        }
         const size_t buffer_size = max_buffer_period_size_frames * frame_size_in_bytes;
         SUBMIX_ALOGV("adev_get_input_buffer_size() returns %zu bytes, %zu frames",
                  buffer_size, max_buffer_period_size_frames);