commit f2595446af5d9bf2ca4b2e5bf07dfbbd842e61ec
author Dominik Laskowski <domlaskowski@google.com> Mon Aug 29 13:51:57 2022 -0700
committer Dominik Laskowski <domlaskowski@google.com> Thu Sep 08 08:46:22 2022 -0700
tree 4b6f0bf4e739375119dfba432e1e465dc061e10d
parent b363c4c28db829bc297e794eac91b02359ff2242

SF: Extract getPreferredDisplayMode

Instead of aborting, error out from setDesiredDisplayModeSpecs if the
display or mode cannot be found (which could happen if the display is
disconnected) or if the mode is disallowed.

Bug: 241285876
Test: Refresh rate switching still works
Change-Id: Ifd7fdce0da596474440eb5195ab3ef3340772a05

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 1bb81c5..ca578e1 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -6744,6 +6744,20 @@
     }
 }
 
+std::optional<DisplayModePtr> SurfaceFlinger::getPreferredDisplayMode(
+        PhysicalDisplayId displayId, DisplayModeId defaultModeId) const {
+    if (const auto schedulerMode = mScheduler->getPreferredDisplayMode();
+        schedulerMode && schedulerMode->getPhysicalDisplayId() == displayId) {
+        return schedulerMode;
+    }
+
+    return mPhysicalDisplays.get(displayId)
+            .transform(&PhysicalDisplay::snapshotRef)
+            .and_then([&](const display::DisplaySnapshot& snapshot) {
+                return snapshot.displayModes().get(defaultModeId);
+            });
+}
+
 status_t SurfaceFlinger::setDesiredDisplayModeSpecsInternal(
         const sp<DisplayDevice>& display,
         const std::optional<scheduler::RefreshRateConfigs::Policy>& policy, bool overridePolicy) {
@@ -6762,7 +6776,7 @@
         return NO_ERROR;
     }
 
-    scheduler::RefreshRateConfigs::Policy currentPolicy =
+    const scheduler::RefreshRateConfigs::Policy currentPolicy =
             display->refreshRateConfigs().getCurrentPolicy();
 
     ALOGV("Setting desired display mode specs: %s", currentPolicy.toString().c_str());
@@ -6777,40 +6791,25 @@
         mScheduler->onNonPrimaryDisplayModeChanged(mAppConnectionHandle, activeMode);
     }
 
-    const DisplayModePtr preferredDisplayMode = [&]() REQUIRES(mStateLock) -> DisplayModePtr {
-        const auto displayId = display->getPhysicalId();
-
-        if (const auto schedulerMode = mScheduler->getPreferredDisplayMode();
-            schedulerMode && schedulerMode->getPhysicalDisplayId() == displayId) {
-            return schedulerMode;
-        }
-
-        const DisplayModePtr nullMode;
-        return mPhysicalDisplays.get(displayId)
-                .transform(&PhysicalDisplay::snapshotRef)
-                .and_then([&](const display::DisplaySnapshot& snapshot) {
-                    return snapshot.displayModes().get(currentPolicy.defaultMode);
-                })
-                .value_or(std::cref(nullMode));
-    }();
-
-    if (!preferredDisplayMode) {
+    auto preferredModeOpt =
+            getPreferredDisplayMode(display->getPhysicalId(), currentPolicy.defaultMode);
+    if (!preferredModeOpt) {
         ALOGE("%s: Preferred mode is unknown", __func__);
         return NAME_NOT_FOUND;
     }
 
-    ALOGV("trying to switch to Scheduler preferred mode %d (%s)",
-          preferredDisplayMode->getId().value(), to_string(preferredDisplayMode->getFps()).c_str());
+    auto preferredMode = std::move(*preferredModeOpt);
+    const auto preferredModeId = preferredMode->getId();
 
-    if (display->refreshRateConfigs().isModeAllowed(preferredDisplayMode->getId())) {
-        ALOGV("switching to Scheduler preferred display mode %d",
-              preferredDisplayMode->getId().value());
-        setDesiredActiveMode({preferredDisplayMode, DisplayModeEvent::Changed});
-    } else {
-        LOG_ALWAYS_FATAL("Desired display mode not allowed: %d",
-                         preferredDisplayMode->getId().value());
+    ALOGV("Switching to Scheduler preferred mode %d (%s)", preferredModeId.value(),
+          to_string(preferredMode->getFps()).c_str());
+
+    if (!display->refreshRateConfigs().isModeAllowed(preferredModeId)) {
+        ALOGE("%s: Preferred mode %d is disallowed", __func__, preferredModeId.value());
+        return INVALID_OPERATION;
     }
 
+    setDesiredActiveMode({std::move(preferredMode), DisplayModeEvent::Changed});
     return NO_ERROR;
 }
 

services/surfaceflinger/SurfaceFlinger.h

diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index e9e13ef..2af17e7 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -668,6 +668,12 @@
     // Returns true if the display has a visible HDR layer in its layer stack.
     bool hasVisibleHdrLayer(const sp<DisplayDevice>& display) REQUIRES(mStateLock);
 
+    // Returns the preferred mode for PhysicalDisplayId if the Scheduler has selected one for that
+    // display. Falls back to the display's defaultModeId otherwise.
+    std::optional<DisplayModePtr> getPreferredDisplayMode(PhysicalDisplayId,
+                                                          DisplayModeId defaultModeId) const
+            REQUIRES(mStateLock);
+
     // Sets the desired display mode specs.
     status_t setDesiredDisplayModeSpecsInternal(
             const sp<DisplayDevice>& display,