SF: Let DM resize framebuffer on resolution change

The goal of this change is to synchronize resolution switching across SF
and DM. The lack of synchronization causes glitches, which are currently
papered over in HWC by dropping frames whose size don't match the active
resolution.

A mode set involving a resolution switch was finalized by destroying the
DisplayDevice and thus its HWC layers. Remove this special case in favor
of letting DM call SurfaceControl.setDisplaySize right after requesting
the mode set via setDesiredDisplayModeSpecs.

Emit a mode change event to DM as soon as the DisplayModeRequest becomes
the desired mode. In response, DM sends the transaction that resizes the
display via setDisplaySize, so wait until that commit before modesetting
to the new resolution, and resize the framebuffer in that same frame.

Display projection depends on display size, so update the latter first
when committing DisplayDeviceState.

Fixes: 355427258
Flag: com.android.graphics.surfaceflinger.flags.synced_resolution_switch
Test: Internal (caiman) and external displays, with different rotations.
Test: Inner display (comet) with install orientation.
Change-Id: Ifaf300f3b5f907f7cd10b8db2aa6165ad2106530

1 files changed, 1 insertions, 3 deletions

diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index c743ea2ff4..e8b09b043e 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -223,9 +223,7 @@ void DisplayDevice::setFlags(uint32_t flags) {
     mFlags = flags;
 }
 
-void DisplayDevice::setDisplaySize(int width, int height) {
-    LOG_FATAL_IF(!isVirtual(), "Changing the display size is supported only for virtual displays.");
-    const auto size = ui::Size(width, height);
+void DisplayDevice::setDisplaySize(ui::Size size) {
     mCompositionDisplay->setDisplaySize(size);
     if (mRefreshRateOverlay) {
         mRefreshRateOverlay->setViewport(size);