SF: Move toggleKernelIdleTimer to DMC

Remove a special case for the default display by tracking the enabled
state per display.

Bug: 241285876
Bug: 355424160
Flag: EXEMPT refactor
Test: presubmit
Change-Id: Ife697e9f31bdf833910132fb0a71918b29c350eb
diff --git a/services/surfaceflinger/Display/DisplayModeController.cpp b/services/surfaceflinger/Display/DisplayModeController.cpp
index c43d585..0e9218c 100644
--- a/services/surfaceflinger/Display/DisplayModeController.cpp
+++ b/services/surfaceflinger/Display/DisplayModeController.cpp
@@ -22,7 +22,9 @@
 #include "Display/DisplaySnapshot.h"
 #include "DisplayHardware/HWComposer.h"
 
+#include <android-base/properties.h>
 #include <common/FlagManager.h>
+#include <common/trace.h>
 #include <ftl/concat.h>
 #include <ftl/expected.h>
 #include <log/log.h>
@@ -237,4 +239,63 @@
     }
 }
 
+void DisplayModeController::updateKernelIdleTimer(PhysicalDisplayId displayId) {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr = FTL_TRY(mDisplays.get(displayId).ok_or(ftl::Unit())).get();
+
+    const auto controllerOpt = displayPtr->selectorPtr->kernelIdleTimerController();
+    if (!controllerOpt) return;
+
+    using KernelIdleTimerAction = scheduler::RefreshRateSelector::KernelIdleTimerAction;
+
+    switch (displayPtr->selectorPtr->getIdleTimerAction()) {
+        case KernelIdleTimerAction::TurnOff:
+            if (displayPtr->isKernelIdleTimerEnabled) {
+                SFTRACE_INT("KernelIdleTimer", 0);
+                updateKernelIdleTimer(displayId, std::chrono::milliseconds::zero(), *controllerOpt);
+                displayPtr->isKernelIdleTimerEnabled = false;
+            }
+            break;
+        case KernelIdleTimerAction::TurnOn:
+            if (!displayPtr->isKernelIdleTimerEnabled) {
+                SFTRACE_INT("KernelIdleTimer", 1);
+                const auto timeout = displayPtr->selectorPtr->getIdleTimerTimeout();
+                updateKernelIdleTimer(displayId, timeout, *controllerOpt);
+                displayPtr->isKernelIdleTimerEnabled = true;
+            }
+            break;
+    }
+}
+
+void DisplayModeController::updateKernelIdleTimer(PhysicalDisplayId displayId,
+                                                  std::chrono::milliseconds timeout,
+                                                  KernelIdleTimerController controller) {
+    switch (controller) {
+        case KernelIdleTimerController::HwcApi:
+            mComposerPtr->setIdleTimerEnabled(displayId, timeout);
+            break;
+
+        case KernelIdleTimerController::Sysprop:
+            using namespace std::string_literals;
+            base::SetProperty("graphics.display.kernel_idle_timer.enabled"s,
+                              timeout > std::chrono::milliseconds::zero() ? "true"s : "false"s);
+            break;
+    }
+}
+
+auto DisplayModeController::getKernelIdleTimerState(PhysicalDisplayId displayId) const
+        -> KernelIdleTimerState {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr =
+            FTL_EXPECT(mDisplays.get(displayId).ok_or(KernelIdleTimerState())).get();
+
+    const auto desiredModeIdOpt =
+            (std::scoped_lock(displayPtr->desiredModeLock), displayPtr->desiredModeOpt)
+                    .transform([](const display::DisplayModeRequest& request) {
+                        return request.mode.modePtr->getId();
+                    });
+
+    return {desiredModeIdOpt, displayPtr->isKernelIdleTimerEnabled};
+}
+
 } // namespace android::display
diff --git a/services/surfaceflinger/Display/DisplayModeController.h b/services/surfaceflinger/Display/DisplayModeController.h
index 258b04b..9ec603d 100644
--- a/services/surfaceflinger/Display/DisplayModeController.h
+++ b/services/surfaceflinger/Display/DisplayModeController.h
@@ -97,6 +97,17 @@
     void setActiveMode(PhysicalDisplayId, DisplayModeId, Fps vsyncRate, Fps renderFps)
             EXCLUDES(mDisplayLock);
 
+    void updateKernelIdleTimer(PhysicalDisplayId) REQUIRES(kMainThreadContext)
+            EXCLUDES(mDisplayLock);
+
+    struct KernelIdleTimerState {
+        std::optional<DisplayModeId> desiredModeIdOpt = std::nullopt;
+        bool isEnabled = false;
+    };
+
+    KernelIdleTimerState getKernelIdleTimerState(PhysicalDisplayId) const
+            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+
 private:
     struct Display {
         template <size_t N>
@@ -121,6 +132,8 @@
 
         DisplayModeRequestOpt pendingModeOpt GUARDED_BY(kMainThreadContext);
         bool isModeSetPending GUARDED_BY(kMainThreadContext) = false;
+
+        bool isKernelIdleTimerEnabled GUARDED_BY(kMainThreadContext) = false;
     };
 
     using DisplayPtr = std::unique_ptr<Display>;
@@ -128,6 +141,10 @@
     void setActiveModeLocked(PhysicalDisplayId, DisplayModeId, Fps vsyncRate, Fps renderFps)
             REQUIRES(mDisplayLock);
 
+    using KernelIdleTimerController = scheduler::RefreshRateSelector::KernelIdleTimerController;
+    void updateKernelIdleTimer(PhysicalDisplayId, std::chrono::milliseconds timeout,
+                               KernelIdleTimerController) REQUIRES(mDisplayLock);
+
     // Set once when initializing the DisplayModeController, which the HWComposer must outlive.
     HWComposer* mComposerPtr = nullptr;
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 9633cc5..b8c69a0 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -205,8 +205,6 @@
 using ui::DisplayPrimaries;
 using ui::RenderIntent;
 
-using KernelIdleTimerController = scheduler::RefreshRateSelector::KernelIdleTimerController;
-
 namespace hal = android::hardware::graphics::composer::hal;
 
 namespace {
@@ -374,8 +372,6 @@
 const String16 sInternalSystemWindow("android.permission.INTERNAL_SYSTEM_WINDOW");
 const String16 sWakeupSurfaceFlinger("android.permission.WAKEUP_SURFACE_FLINGER");
 
-const char* KERNEL_IDLE_TIMER_PROP = "graphics.display.kernel_idle_timer.enabled";
-
 // ---------------------------------------------------------------------------
 int64_t SurfaceFlinger::dispSyncPresentTimeOffset;
 bool SurfaceFlinger::useHwcForRgbToYuv;
@@ -6945,7 +6941,7 @@
 
     // Update the overlay on the main thread to avoid race conditions with
     // RefreshRateSelector::getActiveMode
-    static_cast<void>(mScheduler->schedule([=, this] {
+    static_cast<void>(mScheduler->schedule([=, this]() FTL_FAKE_GUARD(kMainThreadContext) {
         const auto display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked());
         if (!display) {
             ALOGW("%s: default display is null", __func__);
@@ -6953,15 +6949,9 @@
         }
         if (!display->isRefreshRateOverlayEnabled()) return;
 
-        const auto desiredModeIdOpt =
-                mDisplayModeController.getDesiredMode(display->getPhysicalId())
-                        .transform([](const display::DisplayModeRequest& request) {
-                            return request.mode.modePtr->getId();
-                        });
+        const auto state = mDisplayModeController.getKernelIdleTimerState(display->getPhysicalId());
 
-        const bool timerExpired = mKernelIdleTimerEnabled && expired;
-
-        if (display->onKernelTimerChanged(desiredModeIdOpt, timerExpired)) {
+        if (display->onKernelTimerChanged(state.desiredModeIdOpt, state.isEnabled && expired)) {
             mScheduler->scheduleFrame();
         }
     }));
@@ -6983,8 +6973,8 @@
     }));
 }
 
-std::pair<std::optional<KernelIdleTimerController>, std::chrono::milliseconds>
-SurfaceFlinger::getKernelIdleTimerProperties(PhysicalDisplayId displayId) {
+auto SurfaceFlinger::getKernelIdleTimerProperties(PhysicalDisplayId displayId)
+        -> std::pair<std::optional<KernelIdleTimerController>, std::chrono::milliseconds> {
     const bool isKernelIdleTimerHwcSupported = getHwComposer().getComposer()->isSupported(
             android::Hwc2::Composer::OptionalFeature::KernelIdleTimer);
     const auto timeout = getIdleTimerTimeout(displayId);
@@ -7008,63 +6998,6 @@
     return {std::nullopt, timeout};
 }
 
-void SurfaceFlinger::updateKernelIdleTimer(std::chrono::milliseconds timeout,
-                                           KernelIdleTimerController controller,
-                                           PhysicalDisplayId displayId) {
-    switch (controller) {
-        case KernelIdleTimerController::HwcApi: {
-            getHwComposer().setIdleTimerEnabled(displayId, timeout);
-            break;
-        }
-        case KernelIdleTimerController::Sysprop: {
-            base::SetProperty(KERNEL_IDLE_TIMER_PROP, timeout > 0ms ? "true" : "false");
-            break;
-        }
-    }
-}
-
-void SurfaceFlinger::toggleKernelIdleTimer() {
-    using KernelIdleTimerAction = scheduler::RefreshRateSelector::KernelIdleTimerAction;
-
-    const auto display = getDefaultDisplayDeviceLocked();
-    if (!display) {
-        ALOGW("%s: default display is null", __func__);
-        return;
-    }
-
-    // If the support for kernel idle timer is disabled for the active display,
-    // don't do anything.
-    const std::optional<KernelIdleTimerController> kernelIdleTimerController =
-            display->refreshRateSelector().kernelIdleTimerController();
-    if (!kernelIdleTimerController.has_value()) {
-        return;
-    }
-
-    const KernelIdleTimerAction action = display->refreshRateSelector().getIdleTimerAction();
-
-    switch (action) {
-        case KernelIdleTimerAction::TurnOff:
-            if (mKernelIdleTimerEnabled) {
-                SFTRACE_INT("KernelIdleTimer", 0);
-                std::chrono::milliseconds constexpr kTimerDisabledTimeout = 0ms;
-                updateKernelIdleTimer(kTimerDisabledTimeout, kernelIdleTimerController.value(),
-                                      display->getPhysicalId());
-                mKernelIdleTimerEnabled = false;
-            }
-            break;
-        case KernelIdleTimerAction::TurnOn:
-            if (!mKernelIdleTimerEnabled) {
-                SFTRACE_INT("KernelIdleTimer", 1);
-                const std::chrono::milliseconds timeout =
-                        display->refreshRateSelector().getIdleTimerTimeout();
-                updateKernelIdleTimer(timeout, kernelIdleTimerController.value(),
-                                      display->getPhysicalId());
-                mKernelIdleTimerEnabled = true;
-            }
-            break;
-    }
-}
-
 // A simple RAII class to disconnect from an ANativeWindow* when it goes out of scope
 class WindowDisconnector {
 public:
@@ -7951,7 +7884,7 @@
 
     if (const bool isPacesetter =
                 mScheduler->onDisplayModeChanged(displayId, selector.getActiveMode())) {
-        toggleKernelIdleTimer();
+        mDisplayModeController.updateKernelIdleTimer(displayId);
     }
 
     auto preferredModeOpt = getPreferredDisplayMode(displayId, currentPolicy.defaultMode);
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 8b71f3b..b9e9f44 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -707,22 +707,13 @@
     // ICEPowerCallback overrides:
     void notifyCpuLoadUp() override;
 
-    // Toggles the kernel idle timer on or off depending the policy decisions around refresh rates.
-    void toggleKernelIdleTimer() REQUIRES(mStateLock);
-
     using KernelIdleTimerController = scheduler::RefreshRateSelector::KernelIdleTimerController;
 
     // Get the controller and timeout that will help decide how the kernel idle timer will be
     // configured and what value to use as the timeout.
     std::pair<std::optional<KernelIdleTimerController>, std::chrono::milliseconds>
             getKernelIdleTimerProperties(PhysicalDisplayId) REQUIRES(mStateLock);
-    // Updates the kernel idle timer either through HWC or through sysprop
-    // depending on which controller is provided
-    void updateKernelIdleTimer(std::chrono::milliseconds timeoutMs, KernelIdleTimerController,
-                               PhysicalDisplayId) REQUIRES(mStateLock);
-    // Keeps track of whether the kernel idle timer is currently enabled, so we don't have to
-    // make calls to sys prop each time.
-    bool mKernelIdleTimerEnabled = false;
+
     // Show spinner with refresh rate overlay
     bool mRefreshRateOverlaySpinner = false;
     // Show render rate with refresh rate overlay