fix: quench RGB after fan register writes

README.md

@@ -69,7 +69,7 @@ CHECK STORAGE
 
 ### 4. DisplayController、OLED 与 RGB
 
-每个当前故障都是 DisplayController 中的一个 active request，包含稳定 ID、priority、severity、OLED 显示数据、首次发现时间、最后变化时间和元数据。监控只提交或清除 request，同一轮采样作为一个原子批次，全部更新后只仲裁一次。DisplayController 始终只选一个最高优先级 owner；同一 ID 更新原请求而不重复入队，恢复时删除请求，同优先级新 request 排队而不抢占，owner 恢复后按 priority、first_seen、ID 重新仲裁。OLED 在主页和全部当前告警页之间轮播，告警页右上角显示 `当前页/告警总数`，新 owner 会立即抢占一次 OLED。告警页显示时 RGB 同步表达该页对象；回到主页时 RGB 保持最高优先级 active owner，全部恢复后才 OFF。历史 power flags 只进入 diagnose 和一次性 Journal 记录。
+每个当前故障都是 DisplayController 中的一个 active request，包含稳定 ID、priority、severity、OLED 显示数据、首次发现时间、最后变化时间和元数据。监控只提交或清除 request，同一轮采样作为一个原子批次，全部更新后只仲裁一次。DisplayController 始终只选一个最高优先级 owner；同一 ID 更新原请求而不重复入队，恢复时删除请求，同优先级新 request 排队而不抢占，owner 恢复后按 priority、first_seen、ID 重新仲裁。OLED 与 RGB 分别由专属工作线程驱动，监控主循环只更新共享显示状态；OLED 在主页和全部当前告警页之间轮播，告警页右上角显示 `当前页/告警总数`，新 owner 会立即唤醒 OLED 线程。告警页显示时 RGB 同步表达该页对象；回到主页时 RGB 保持最高优先级 active owner，全部恢复后才 OFF。相邻 OLED 页面需要的 RGB mode 相同时，RGB 线程不写寄存器、不重置动画相位。 风扇与 RGB 共用 MCU 0x0D；RGB 正在告警闪烁时，风扇档位命令排到灭灯阶段写入，并在写入后重新确认 RGB OFF，以 `FAN_LEVEL` 事件记录实际写入。历史 power flags 只进入 diagnose 和一次性 Journal 记录。
 
 ### 5. RGB 正常状态与告警引擎
 

SHA256SUMS

@@ -1,10 +1,10 @@
-96dfd20c3ad16ca62a46d66eb5ffb82b1f7f987e66c4dae5310609b1989b7dae  README.md
+4ac63c19d60ed3bb9d804727fe3d373a338f8203a2730a63876fb1845574822c  README.md
 72c46162c33f9587c6ccb01ad53fbaaf4ecec8cd21014b909e87e8707e253e36  app/oled_font_5x7.bin
-d0fa68951097a90eb6f51b36e56dc935d8fd7632c3de0ad6bff0b448960a7c03  app/pigway_pi_control.py
+e925e9b4720b24f2c802cdb746cfa9e2f5af1de84a7533acb09ab1efcce73a82  app/pigway_pi_control.py
 034931590d83969f9f24222cc57800ab193588beea3d3dcedb98f1690000370d  app/pigway_pi_control_api.py
 ee0f682e8016f75f906d974f00c3e3340edddf30447d441ddfd61a7a34c9e83c  config/pigway-pi-control.conf
 f9fbb4defa45b43abe0ce66973b1f4d553369b3a43c01d04f206c573f7dc96ca  install.sh
-4f6e8db3698a62f57823d3298a0e6814593de6fa3d31e4751b7ea4a76e553e35  systemd/pigway-pi-control.service
+33a681e896cae05b9e9d5f89c5387036c9c1ea48d4db937ae03e5cdb7322705d  systemd/pigway-pi-control.service
 aa21cef9a06593371ccff005335b6c0c826fbf4b5c48e4255b5f4b75ce6e9217  systemd/pigway-pi-control-api.service
 9f59e7313ee58e687ae6dd29d175c67082674254ac5c5f54168b2735b64c20a4  uninstall.sh
-3a40109f11bea2d44e9d61bed4a90499a5047c4fc534f97aaa90becbf9e57017  web/index.html
+27454feccb83ad23342fa9d66caed60d568beeed4862852df98a3bc82bf5b6e3  web/index.html

app/pigway_pi_control.py

@@ -98,6 +98,9 @@ def bus_write(method,*args):
             raise
 
 fan_level=0
+fan_initialized=False
+pending_fan=None
+pending_fan_lock=threading.Lock()
 prev_cpu=None
 page=0; page_since=time.monotonic()
 cpu_hi=mem_hi=0
@@ -180,13 +183,36 @@ def fan_target(t):
     if t<FAN_T[4]: return 4
     return 5
 def update_fan(t):
-    global fan_level
+    global fan_level,fan_initialized,pending_fan
-    want=fan_target(t); old=fan_level
+    want=fan_target(t); old=fan_level if fan_initialized else None
     if want>fan_level: fan_level=want
     elif want<fan_level:
         boundary = FAN_T[max(0,fan_level-1)] - FAN_HYST
         if t < boundary: fan_level-=1
-    if old!=fan_level: mcu(0x08,FAN_REG[fan_level])
+    if not fan_initialized or old!=fan_level:
+        with pending_fan_lock:
+            pending_fan=(old,fan_level,float(t))
+    fan_initialized=True
+
+def apply_pending_fan(keep_rgb_off=False):
+    global pending_fan
+    with pending_fan_lock:
+        command=pending_fan
+        pending_fan=None
+    if command is None: return
+    old,new,temp=command
+    try:
+        mcu(0x08,FAN_REG[new])
+        # Some revisions of the shared MCU briefly expose their previous RGB
+        # state after a fan-register write.  When the flash engine is already
+        # in its dark phase, immediately reassert OFF without changing phase.
+        if keep_rgb_off: mcu(0x07,0x00)
+    except Exception:
+        with pending_fan_lock:
+            if pending_fan is None: pending_fan=command
+        raise
+    log("INFO","FAN_LEVEL",old=FAN_NAME[old] if old is not None else "UNKNOWN",
+        new=FAN_NAME[new],temp_c=f"{temp:.1f}",register=f"0x{FAN_REG[new]:02x}")
 
 def cpu_pct():
     global prev_cpu
@@ -493,9 +519,12 @@ def rgb_flash(mode,on):
     if not on:
         mcu(0x07,0x00)
     else:
-        mcu(0x00,0xff); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+        # Keep the seller's selector -> R -> G -> B protocol contiguous.  A
-        mcu(0x01,channels[0]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+        # visible delay between these writes lets the MCU render stale partial
-        mcu(0x02,channels[1]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+        # channel data, which appears as a brief unrelated color or chase.
+        mcu(0x00,0xff)
+        mcu(0x01,channels[0])
+        mcu(0x02,channels[1])
         mcu(0x03,channels[2])
     _last_rgb=state
 
@@ -503,10 +532,10 @@ def rgb_static(channels,state_name):
     global _last_rgb
     state=(state_name,channels)
     if _last_rgb==state: return
-    mcu(0x07,0x00); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+    mcu(0x07,0x00)
-    mcu(0x00,0xff); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+    mcu(0x00,0xff)
-    mcu(0x01,channels[0]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+    mcu(0x01,channels[0])
-    mcu(0x02,channels[1]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
+    mcu(0x02,channels[1])
     mcu(0x03,channels[2])
     _last_rgb=state
 
@@ -579,10 +608,12 @@ class DisplayController:
         self.page_started=now
         self.batch_depth=0
         self.stop_event=threading.Event()
+        self.oled_wake=threading.Event()
+        self.oled_thread=threading.Thread(target=self._oled_worker,name="oled",daemon=True)
         self.rgb_thread=threading.Thread(target=self._rgb_worker,name="rgb",daemon=True)
 
     def start(self):
-        oled_init(); self.refresh(); rgb_off(); self.rgb_thread.start()
+        oled_init(); rgb_off(); self.oled_thread.start(); self.rgb_thread.start()
 
     def update_home(self,cpu,temp,mem,disk):
         with self.lock:
@@ -620,7 +651,7 @@ class DisplayController:
                 if self.batch_depth==0:
                     self._arbitrate_locked()
                     if self.current_oled_page_id not in self.requests:
-                        self._show_page_locked(self.current_owner_id)
+                        self._select_page_locked(self.current_owner_id)
                     else: self._sync_rgb_locked()
 
     def begin_update(self):
@@ -633,7 +664,7 @@ class DisplayController:
             if self.batch_depth==0:
                 self._arbitrate_locked()
                 if self.current_oled_page_id not in self.requests:
-                    self._show_page_locked(self.current_owner_id)
+                    self._select_page_locked(self.current_owner_id)
                 else: self._sync_rgb_locked()
 
     def _arbitrate_locked(self):
@@ -651,23 +682,18 @@ class DisplayController:
         self.current_rgb_mode=request["rgb_mode"]
         self.owner_since=time.monotonic()
         log("INFO","DISPLAY_OWNER",old=old,new=request["id"],priority=request["priority"])
-        self._show_page_locked(request["id"])
+        self._select_page_locked(request["id"])
 
     def _ordered_alerts_locked(self):
         return sorted((r for r in self.requests.values() if r["id"]!="NORMAL_HOME"),
                       key=lambda r:(-r["priority"],r["first_seen"],r["id"]))
 
-    def _show_page_locked(self,page_id):
+    def _select_page_locked(self,page_id,wake=True):
-        alerts=self._ordered_alerts_locked()
         request=self.requests.get(page_id,self.requests["NORMAL_HOME"])
         self.current_oled_page_id=request["id"]
         self.page_started=time.monotonic()
         self._sync_rgb_locked()
-        if request["id"]=="NORMAL_HOME":
+        if wake: self.oled_wake.set()
-            render_home(*request["metadata"]["home"])
-        else:
-            alert_ids=[a["id"] for a in alerts]
-            render_alert(request,alert_ids.index(request["id"])+1,len(alerts))
 
     def _sync_rgb_locked(self):
         # Alert pages show that alert's object color.  HOME keeps the highest-
@@ -677,24 +703,23 @@ class DisplayController:
             rgb_request=self.requests.get(self.current_owner_id,self.requests["NORMAL_HOME"])
         if rgb_request is None:
             rgb_request=self.requests["NORMAL_HOME"]
-        self.current_rgb_mode=rgb_request["rgb_mode"]
+        wanted_mode=rgb_request["rgb_mode"]
+        if wanted_mode!=self.current_rgb_mode:
+            self.current_rgb_mode=wanted_mode
 
     def refresh(self):
         with self.lock:
             alerts=self._ordered_alerts_locked()
             pages=["NORMAL_HOME"]+[a["id"] for a in alerts]
             if self.current_oled_page_id not in pages:
-                self._show_page_locked(self.current_owner_id)
+                self._select_page_locked(self.current_owner_id,wake=False)
-                return
+            elif len(pages)>1 and time.monotonic()-self.page_started>=PAGE_INTERVAL:
-            if len(pages)>1 and time.monotonic()-self.page_started>=PAGE_INTERVAL:
                 pos=pages.index(self.current_oled_page_id)
-                self._show_page_locked(pages[(pos+1)%len(pages)])
+                self._select_page_locked(pages[(pos+1)%len(pages)],wake=False)
-                return
+            request=dict(self.requests[self.current_oled_page_id])
-            request=self.requests[self.current_oled_page_id]
+            alert_ids=[a["id"] for a in alerts]
-            if request["id"]=="NORMAL_HOME": render_home(*request["metadata"]["home"])
+        if request["id"]=="NORMAL_HOME": render_home(*request["metadata"]["home"])
-            else:
+        else: render_alert(request,alert_ids.index(request["id"])+1,len(alerts))
-                alert_ids=[a["id"] for a in alerts]
-                render_alert(request,alert_ids.index(request["id"])+1,len(alerts))
 
     def owner_snapshot(self):
         with self.lock: return dict(self.requests[self.current_owner_id])
@@ -710,6 +735,19 @@ class DisplayController:
                           for a in alerts],
             }
 
+    def _oled_worker(self):
+        previous_error=None
+        while not self.stop_event.is_set():
+            self.oled_wake.clear()
+            try:
+                self.refresh()
+                if previous_error is not None: log("INFO","OLED_RECOVERED")
+                previous_error=None
+            except Exception as e:
+                if repr(e)!=previous_error: log("ERROR","OLED_ERROR",error=repr(e))
+                previous_error=repr(e)
+            self.oled_wake.wait(OLED_REFRESH)
+
     def _rgb_worker(self):
         previous_error=None; applied_mode="OFF"; applied_flash=False
         flash_on=None; animation_started=time.monotonic()
@@ -744,6 +782,11 @@ class DisplayController:
                                 rgb_static(NORMAL_COLOR,"normal_flash_on") if on else rgb_off()
                             else: rgb_flash(applied_mode,on)
                         flash_on=on
+                # Fan and RGB share the same MCU.  During an alert flash, send
+                # fan changes only while RGB is already dark so MCU-internal
+                # register handling cannot expose a transient unrelated color.
+                if not applied_flash or flash_on is False:
+                    with bus_lock: apply_pending_fan(keep_rgb_off=applied_flash)
                 if previous_error is not None: log("INFO","RGB_RECOVERED")
                 previous_error=None
             except Exception as e:
@@ -754,6 +797,8 @@ class DisplayController:
 
     def shutdown(self):
         self.stop_event.set()
+        self.oled_wake.set()
+        if self.oled_thread.is_alive(): self.oled_thread.join()
         if self.rgb_thread.is_alive(): self.rgb_thread.join()
         for name,action in (("rgb",rgb_off),("oled_clear",lambda:oled_show([("","")]*4)),
                             ("oled_off",lambda:cmd(0xAE))):
@@ -808,7 +853,7 @@ args=parser.parse_args()
 if args.diagnose: raise SystemExit(diagnose())
 
 watch_state=[]
-last_sensor=last_render=last_status=0.0
+last_sensor=last_status=0.0
 last_net=last_watch=last_health=0.0
 health={}; fs_readonly=False
 agent={"last_sensor_ok":0.0,"last_network_ok":0.0,"last_watch_ok":0.0,"last_health_ok":0.0,"loop_errors":0,"i2c_errors":0}
@@ -818,6 +863,9 @@ latest=(0.0,0.0,0.0,0.0)
 display=DisplayController()
 try:
     bus=SMBus(1)
+    # Quench the MCU's power-on RGB effect before OLED initialization and all
+    # other startup work.  The display controller remains the sole RGB owner.
+    rgb_off()
     FONT5=Path(FONT_PATH).read_bytes()
     display.start(); apply_dark_mode()
     log("INFO","START",version=APP_VERSION,uptime=uptime_seconds())
@@ -868,9 +916,6 @@ try:
             display.begin_update()
             try: update_active_alerts(c,t,m,d,sample_elapsed)
             finally: display.end_update()
-            if now-last_render >= OLED_REFRESH:
-                display.refresh()
-                last_render=now
             if now-last_status >= 1.0:
                 write_status(c,t,m,d); last_status=now
 

systemd/pigway-pi-control.service

@@ -1,7 +1,7 @@
 [Unit]
 Description=PIGWay Raspberry Pi OLED/Fan/RGB Monitor
-After=multi-user.target network.target
+After=local-fs.target systemd-modules-load.service
-Wants=network.target
+Before=multi-user.target
 
 [Service]
 Type=simple