Handle edge cases for E-Ink screensaver (#3518)

* remove redundant logic

* Handle special screens for old EInkDisplayClass

* Handle special screens for EInkDynamicDisplay class

* Join an async refresh in progress to avoid skipping screensaver

* attempt trunk fix

src/graphics/EInkDynamicDisplay.cpp

@@ -463,10 +463,33 @@ void EInkDynamicDisplay::onNotify(uint32_t notification)
 }
 
 #ifdef HAS_EINK_ASYNCFULL
-// Run the post-update code if the hardware is ready
+// Public: wait for an refresh already in progress, then run the post-update code. See Screen::setScreensaverFrames()
+void EInkDynamicDisplay::joinAsyncRefresh()
+{
+    // If no async refresh running, nothing to do
+    if (!asyncRefreshRunning)
+        return;
+
+    LOG_DEBUG("Joining an async refresh in progress\n");
+
+    // Continually poll the BUSY pin
+    while (adafruitDisplay->epd2.isBusy())
+        yield();
+
+    // If asyncRefreshRunning flag is still set, but display's BUSY pin reports the refresh is done
+    adafruitDisplay->endAsyncFull(); // Run the end of nextPage() code
+    EInkDisplay::endUpdate();        // Run base-class code to finish off update (NOT our derived class override)
+    asyncRefreshRunning = false;     // Unset the flag
+    LOG_DEBUG("Refresh complete\n");
+
+    // Note: this code only works because of a modification to meshtastic/GxEPD2.
+    // It is only equipped to intercept calls to nextPage()
+}
+
+// Called from NotifiedWorkerThread. Run the post-update code if the hardware is ready
 void EInkDynamicDisplay::pollAsyncRefresh()
 {
-    // We shouldn't be here..
+    // In theory, this condition should never be met
     if (!asyncRefreshRunning)
         return;
 

src/graphics/EInkDynamicDisplay.h

@@ -119,20 +119,30 @@ class EInkDynamicDisplay : public EInkDisplay, protected concurrency::NotifiedWo
 
     // Conditional - async full refresh - only with modified meshtastic/GxEPD2
 #if defined(HAS_EINK_ASYNCFULL)
+  public:
+    void joinAsyncRefresh(); // Main thread joins an async refresh already in progress. Blocks, then runs post-update code
+
+  protected:
     void pollAsyncRefresh();          // Run the post-update code if the hardware is ready
     void checkBusyAsyncRefresh();     // Check if display is busy running an async full-refresh (rejecting new frames)
     void awaitRefresh();              // Hold control while an async refresh runs
     void endUpdate() override {}      // Disable base-class behavior of running post-update immediately after forceDisplay()
     bool asyncRefreshRunning = false; // Flag, checked by checkBusyAsyncRefresh()
 #else
+  public:
+    void joinAsyncRefresh() {} // Dummy method
+
+  protected:
     void pollAsyncRefresh() {} // Dummy method. In theory, not reachable
 #endif
 };
 
-// Tidier calls to addFrameFlag() from outside class
+// Hide the ugly casts used in Screen.cpp
 #define EINK_ADD_FRAMEFLAG(display, flag) static_cast<EInkDynamicDisplay *>(display)->addFrameFlag(EInkDynamicDisplay::flag)
+#define EINK_JOIN_ASYNCREFRESH(display) static_cast<EInkDynamicDisplay *>(display)->joinAsyncRefresh()
 
 #else // !USE_EINK_DYNAMICDISPLAY
 // Dummy-macro, removes the need for include guards
 #define EINK_ADD_FRAMEFLAG(display, flag)
+#define EINK_JOIN_ASYNCREFRESH(display)
 #endif

src/graphics/Screen.cpp

@@ -1349,6 +1349,12 @@ void Screen::setScreensaverFrames(FrameCallback einkScreensaver)
     static FrameCallback screensaverFrame;
     static OverlayCallback screensaverOverlay;
 
+#if defined(HAS_EINK_ASYNCFULL) && defined(USE_EINK_DYNAMICDISPLAY)
+    // Join (await) a currently running async refresh, then run the post-update code.
+    // Avoid skipping of screensaver frame. Would otherwise be handled by NotifiedWorkerThread.
+    EINK_JOIN_ASYNCREFRESH(dispdev);
+#endif
+
     // If: one-off screensaver frame passed as argument. Handles doDeepSleep()
     if (einkScreensaver != NULL) {
         screensaverFrame = einkScreensaver;
@@ -1370,10 +1376,9 @@ void Screen::setScreensaverFrames(FrameCallback einkScreensaver)
         ui->update();
     } while (ui->getUiState()->lastUpdate < startUpdate);
 
-#ifndef USE_EINK_DYNAMICDISPLAY
-    // Retrofit to EInkDisplay class
-    delay(10);
-    screen->forceDisplay();
+    // Old EInkDisplay class
+#if !defined(USE_EINK_DYNAMICDISPLAY)
+    static_cast<EInkDisplay *>(dispdev)->forceDisplay(0); // Screen::forceDisplay(), but override rate-limit
 #endif
 
     // Prepare now for next frame, shown when display wakes
@@ -1490,8 +1495,11 @@ void Screen::handleShutdownScreen()
 {
     LOG_DEBUG("showing shutdown screen\n");
     showingNormalScreen = false;
-    EINK_ADD_FRAMEFLAG(dispdev, DEMAND_FAST); // E-Ink: Use fast-refresh for next frame, no skip please
+#ifdef USE_EINK
+    EINK_ADD_FRAMEFLAG(dispdev, DEMAND_FAST); // Use fast-refresh for next frame, no skip please
     EINK_ADD_FRAMEFLAG(dispdev, BLOCKING);    // Edge case: if this frame is promoted to COSMETIC, wait for update
+    handleSetOn(true);                        // Ensure power-on to receive deep-sleep screensaver (PowerFSM should handle?)
+#endif
 
     auto frame = [](OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y) -> void {
         drawFrameText(display, state, x, y, "Shutting down...");
@@ -1499,14 +1507,17 @@ void Screen::handleShutdownScreen()
     static FrameCallback frames[] = {frame};
 
     setFrameImmediateDraw(frames);
-    forceDisplay();
 }
 
 void Screen::handleRebootScreen()
 {
     LOG_DEBUG("showing reboot screen\n");
     showingNormalScreen = false;
-    EINK_ADD_FRAMEFLAG(dispdev, DEMAND_FAST); // E-Ink: Explicitly use fast-refresh for next frame
+#ifdef USE_EINK
+    EINK_ADD_FRAMEFLAG(dispdev, DEMAND_FAST); // Use fast-refresh for next frame, no skip please
+    EINK_ADD_FRAMEFLAG(dispdev, BLOCKING);    // Edge case: if this frame is promoted to COSMETIC, wait for update
+    handleSetOn(true);                        // Power-on to show rebooting screen (PowerFSM should handle?)
+#endif
 
     auto frame = [](OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y) -> void {
         drawFrameText(display, state, x, y, "Rebooting...");

src/graphics/Screen.h

@@ -150,7 +150,7 @@ class Screen : public concurrency::OSThread
             // We handle off commands immediately, because they might be called because the CPU is shutting down
             handleSetOn(false, einkScreensaver);
         else
-            enqueueCmd(ScreenCmd{.cmd = on ? Cmd::SET_ON : Cmd::SET_OFF});
+            enqueueCmd(ScreenCmd{.cmd = Cmd::SET_ON});
     }
 
     /**

src/platform/nrf52/NRF52Bluetooth.cpp

@@ -1,5 +1,6 @@
 #include "NRF52Bluetooth.h"
 #include "BluetoothCommon.h"
+#include "PowerFSM.h"
 #include "configuration.h"
 #include "main.h"
 #include "mesh/PhoneAPI.h"
@@ -318,6 +319,7 @@ void NRF52Bluetooth::onConnectionSecured(uint16_t conn_handle)
 bool NRF52Bluetooth::onPairingPasskey(uint16_t conn_handle, uint8_t const passkey[6], bool match_request)
 {
     LOG_INFO("BLE pairing process started with passkey %.3s %.3s\n", passkey, passkey + 3);
+    powerFSM.trigger(EVENT_BLUETOOTH_PAIR);
     screen->startBluetoothPinScreen(configuredPasskey);
 
     if (match_request) {