SF: Fix error handling for getDisplayVsyncPeriod

HWC errors were being converted to a status_t of NO_ERROR.

Bug: 241285876
Test: presubmit
Change-Id: I0fcfa426c795adf55a920729bc613a0cd140e87c
diff --git a/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h b/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
index 351cc53..575a30e 100644
--- a/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
+++ b/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
@@ -103,7 +103,7 @@
     MOCK_CONST_METHOD0(isUsingVrComposer, bool());
     MOCK_CONST_METHOD1(getDisplayConnectionType, ui::DisplayConnectionType(PhysicalDisplayId));
     MOCK_CONST_METHOD1(isVsyncPeriodSwitchSupported, bool(PhysicalDisplayId));
-    MOCK_CONST_METHOD2(getDisplayVsyncPeriod, status_t(PhysicalDisplayId, nsecs_t*));
+    MOCK_CONST_METHOD1(getDisplayVsyncPeriod, ftl::Expected<nsecs_t, status_t>(PhysicalDisplayId));
     MOCK_METHOD4(setActiveModeWithConstraints,
                  status_t(PhysicalDisplayId, hal::HWConfigId,
                           const hal::VsyncPeriodChangeConstraints&,
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index 4f81482..5f20cd9 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -239,10 +239,8 @@
         return 0;
     }
 
-    nsecs_t vsyncPeriod;
-    const auto status = mHwComposer.getDisplayVsyncPeriod(physicalId, &vsyncPeriod);
-    if (status == NO_ERROR) {
-        return vsyncPeriod;
+    if (const auto vsyncPeriodOpt = mHwComposer.getDisplayVsyncPeriod(physicalId).value_opt()) {
+        return *vsyncPeriodOpt;
     }
 
     return refreshRateSelector().getActiveMode().modePtr->getVsyncRate().getPeriodNsecs();
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 0c29569..bac24c7 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -380,20 +380,20 @@
     return mDisplayData.at(displayId).hwcDisplay->isVsyncPeriodSwitchSupported();
 }
 
-status_t HWComposer::getDisplayVsyncPeriod(PhysicalDisplayId displayId,
-                                           nsecs_t* outVsyncPeriod) const {
-    RETURN_IF_INVALID_DISPLAY(displayId, 0);
+ftl::Expected<nsecs_t, status_t> HWComposer::getDisplayVsyncPeriod(
+        PhysicalDisplayId displayId) const {
+    RETURN_IF_INVALID_DISPLAY(displayId, ftl::Unexpected(BAD_INDEX));
 
     if (!isVsyncPeriodSwitchSupported(displayId)) {
-        return INVALID_OPERATION;
+        return ftl::Unexpected(INVALID_OPERATION);
     }
+
     const auto hwcId = *fromPhysicalDisplayId(displayId);
     Hwc2::VsyncPeriodNanos vsyncPeriodNanos = 0;
-    auto error =
+    const auto error =
             static_cast<hal::Error>(mComposer->getDisplayVsyncPeriod(hwcId, &vsyncPeriodNanos));
-    RETURN_IF_HWC_ERROR(error, displayId, 0);
-    *outVsyncPeriod = static_cast<nsecs_t>(vsyncPeriodNanos);
-    return NO_ERROR;
+    RETURN_IF_HWC_ERROR(error, displayId, ftl::Unexpected(UNKNOWN_ERROR));
+    return static_cast<nsecs_t>(vsyncPeriodNanos);
 }
 
 std::vector<ui::ColorMode> HWComposer::getColorModes(PhysicalDisplayId displayId) const {
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 6d1d0a5..7fbbb1a 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -248,8 +248,7 @@
     // Composer 2.4
     virtual ui::DisplayConnectionType getDisplayConnectionType(PhysicalDisplayId) const = 0;
     virtual bool isVsyncPeriodSwitchSupported(PhysicalDisplayId) const = 0;
-    virtual status_t getDisplayVsyncPeriod(PhysicalDisplayId displayId,
-                                           nsecs_t* outVsyncPeriod) const = 0;
+    virtual ftl::Expected<nsecs_t, status_t> getDisplayVsyncPeriod(PhysicalDisplayId) const = 0;
     virtual status_t setActiveModeWithConstraints(PhysicalDisplayId, hal::HWConfigId,
                                                   const hal::VsyncPeriodChangeConstraints&,
                                                   hal::VsyncPeriodChangeTimeline* outTimeline) = 0;
@@ -436,8 +435,7 @@
     // Composer 2.4
     ui::DisplayConnectionType getDisplayConnectionType(PhysicalDisplayId) const override;
     bool isVsyncPeriodSwitchSupported(PhysicalDisplayId) const override;
-    status_t getDisplayVsyncPeriod(PhysicalDisplayId displayId,
-                                   nsecs_t* outVsyncPeriod) const override;
+    ftl::Expected<nsecs_t, status_t> getDisplayVsyncPeriod(PhysicalDisplayId) const override;
     status_t setActiveModeWithConstraints(PhysicalDisplayId, hal::HWConfigId,
                                           const hal::VsyncPeriodChangeConstraints&,
                                           hal::VsyncPeriodChangeTimeline* outTimeline) override;
diff --git a/services/surfaceflinger/fuzzer/surfaceflinger_displayhardware_fuzzer.cpp b/services/surfaceflinger/fuzzer/surfaceflinger_displayhardware_fuzzer.cpp
index 68237c8..682079f 100644
--- a/services/surfaceflinger/fuzzer/surfaceflinger_displayhardware_fuzzer.cpp
+++ b/services/surfaceflinger/fuzzer/surfaceflinger_displayhardware_fuzzer.cpp
@@ -143,7 +143,6 @@
     void invokeComposerHal2_2(Hwc2::AidlComposer*, Display, Hwc2::V2_4::hal::Layer);
     void invokeComposerHal2_3(Hwc2::AidlComposer*, Display, Hwc2::V2_4::hal::Layer);
     void invokeComposerHal2_4(Hwc2::AidlComposer*, Display, Hwc2::V2_4::hal::Layer);
-    void getDisplayVsyncPeriod();
     void setActiveModeWithConstraints();
     void getDisplayIdentificationData();
     void dumpHwc();
@@ -202,11 +201,6 @@
     return display;
 }
 
-void DisplayHardwareFuzzer::getDisplayVsyncPeriod() {
-    nsecs_t outVsyncPeriod;
-    mHwc.getDisplayVsyncPeriod(mPhysicalDisplayId, &outVsyncPeriod);
-}
-
 void DisplayHardwareFuzzer::setActiveModeWithConstraints() {
     hal::VsyncPeriodChangeTimeline outTimeline;
     mHwc.setActiveModeWithConstraints(mPhysicalDisplayId, kActiveConfig, {} /*constraints*/,
@@ -617,8 +611,7 @@
 
     mHwc.getDisplayConnectionType(mPhysicalDisplayId);
     mHwc.isVsyncPeriodSwitchSupported(mPhysicalDisplayId);
-
-    getDisplayVsyncPeriod();
+    mHwc.getDisplayVsyncPeriod(mPhysicalDisplayId);
 
     setActiveModeWithConstraints();