camerad: make handle_camera_event readable (#34620)

* renames

* lil more

---------

Co-authored-by: Comma Device <device@comma.ai>

system/camerad/cameras/spectra.cc

@@ -1370,50 +1370,52 @@ void SpectraCamera::camera_close() {
 void SpectraCamera::handle_camera_event(const cam_req_mgr_message *event_data) {
   if (!enabled) return;
 
-  uint64_t timestamp = event_data->u.frame_msg.timestamp;
-  uint64_t main_id = event_data->u.frame_msg.frame_id;
-  uint64_t real_id = event_data->u.frame_msg.request_id;
+  // ID from the qcom camera request manager
+  uint64_t request_id = event_data->u.frame_msg.request_id;
 
-  if (real_id != 0) { // next ready
-    if (real_id == 1) {
-      idx_offset = main_id;
+  // raw as opposed to our re-indexed frame ID
+  uint64_t frame_id_raw = event_data->u.frame_msg.frame_id;
+
+  if (request_id != 0) { // next ready
+    if (request_id == 1) {
+      frame_id_offset = frame_id_raw;
     }
-    int buf_idx = (real_id - 1) % ife_buf_depth;
+    int buf_idx = (request_id - 1) % ife_buf_depth;
 
-    // check for skipped frames
-    if (main_id > frame_id_last + 1 && !skipped) {
+    // check for skipped_last frames
+    if (frame_id_raw > frame_id_raw_last + 1 && !skipped_last) {
       LOGE("camera %d realign", cc.camera_num);
       clear_req_queue();
-      enqueue_req_multi(real_id + 1, ife_buf_depth - 1, 0);
-      skipped = true;
-    } else if (main_id == frame_id_last + 1) {
-      skipped = false;
+      enqueue_req_multi(request_id + 1, ife_buf_depth - 1, 0);
+      skipped_last = true;
+    } else if (frame_id_raw == frame_id_raw_last + 1) {
+      skipped_last = false;
     }
 
     // check for dropped requests
-    if (real_id > request_id_last + 1) {
-      LOGE("camera %d dropped requests %ld %ld", cc.camera_num, real_id, request_id_last);
-      enqueue_req_multi(request_id_last + 1 + ife_buf_depth, real_id - (request_id_last + 1), 0);
+    if (request_id > request_id_last + 1) {
+      LOGE("camera %d dropped requests %ld %ld", cc.camera_num, request_id, request_id_last);
+      enqueue_req_multi(request_id_last + 1 + ife_buf_depth, request_id - (request_id_last + 1), 0);
     }
 
     // metas
-    frame_id_last = main_id;
-    request_id_last = real_id;
+    frame_id_raw_last = frame_id_raw;
+    request_id_last = request_id;
 
     auto &meta_data = buf.frame_metadata[buf_idx];
-    meta_data.frame_id = main_id - idx_offset;
-    meta_data.request_id = real_id;
-    meta_data.timestamp_sof = timestamp; // this is timestamped in the kernel's SOF IRQ callback
+    meta_data.frame_id = frame_id_raw - frame_id_offset;
+    meta_data.request_id = request_id;
+    meta_data.timestamp_sof = event_data->u.frame_msg.timestamp; // this is timestamped in the kernel's SOF IRQ callback
 
-    // dispatch
-    enqueue_req_multi(real_id + ife_buf_depth, 1, 1);
+    // wait for this frame's EOF, then queue up the next one
+    enqueue_req_multi(request_id + ife_buf_depth, 1, 1);
   } else { // not ready
-    if (main_id > frame_id_last + 10) {
+    if (frame_id_raw > frame_id_raw_last + 10) {
       LOGE("camera %d reset after half second of no response", cc.camera_num);
       clear_req_queue();
       enqueue_req_multi(request_id_last + 1, ife_buf_depth, 0);
-      frame_id_last = main_id;
-      skipped = true;
+      frame_id_raw_last = frame_id_raw;
+      skipped_last = true;
     }
   }
 }

system/camerad/cameras/spectra.h

@@ -188,9 +188,9 @@ public:
   int sync_objs_bps[MAX_IFE_BUFS] = {};
   uint64_t request_ids[MAX_IFE_BUFS] = {};
   uint64_t request_id_last = 0;
-  uint64_t frame_id_last = 0;
-  uint64_t idx_offset = 0;
-  bool skipped = true;
+  uint64_t frame_id_raw_last = 0;
+  uint64_t frame_id_offset = 0;
+  bool skipped_last = true;
 
   SpectraOutputType output_type;