commit cf0bb43409962a0184f2e79bac547dd11f07abab
author Dominik Laskowski <domlaskowski@google.com> Tue May 09 11:49:16 2023 -0400
committer Dominik Laskowski <domlaskowski@google.com> Tue May 09 13:06:37 2023 -0400
tree 1bf8444ff5566df3d547e99e6255f131214d8089
parent 9560a12c9524c6929fbfb8986ca779d4de282ddb

SF: Tie main thread priority to active display

Otherwise, the powering off of the outer display when exiting concurrent
mode causes SF to drop real-time priority until the next powering on of
either display.

Fixes: 271431077
Test: Logs during boot, power on/off, fold/unfold, concurrent mode.
Change-Id: I4f1590d7abf82977c1acd162605f578624bc9faa

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 3c55caf..91f945b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -5488,14 +5488,19 @@
             onActiveDisplayChangedLocked(activeDisplay.get(), *display);
         }
 
-        // Keep uclamp in a separate syscall and set it before changing to RT due to b/190237315.
-        // We can merge the syscall later.
-        if (SurfaceFlinger::setSchedAttr(true) != NO_ERROR) {
-            ALOGW("Couldn't set uclamp.min on display on: %s\n", strerror(errno));
+        if (displayId == mActiveDisplayId) {
+            // TODO(b/281692563): Merge the syscalls. For now, keep uclamp in a separate syscall and
+            // set it before SCHED_FIFO due to b/190237315.
+            if (setSchedAttr(true) != NO_ERROR) {
+                ALOGW("Failed to set uclamp.min after powering on active display: %s",
+                      strerror(errno));
+            }
+            if (setSchedFifo(true) != NO_ERROR) {
+                ALOGW("Failed to set SCHED_FIFO after powering on active display: %s",
+                      strerror(errno));
+            }
         }
-        if (SurfaceFlinger::setSchedFifo(true) != NO_ERROR) {
-            ALOGW("Couldn't set SCHED_FIFO on display on: %s\n", strerror(errno));
-        }
+
         getHwComposer().setPowerMode(displayId, mode);
         if (displayId == mActiveDisplayId && mode != hal::PowerMode::DOZE_SUSPEND) {
             setHWCVsyncEnabled(displayId,
@@ -5509,15 +5514,21 @@
         scheduleComposite(FrameHint::kActive);
     } else if (mode == hal::PowerMode::OFF) {
         // Turn off the display
-        if (SurfaceFlinger::setSchedFifo(false) != NO_ERROR) {
-            ALOGW("Couldn't set SCHED_OTHER on display off: %s\n", strerror(errno));
-        }
-        if (SurfaceFlinger::setSchedAttr(false) != NO_ERROR) {
-            ALOGW("Couldn't set uclamp.min on display off: %s\n", strerror(errno));
-        }
-        if (displayId == mActiveDisplayId && *currentModeOpt != hal::PowerMode::DOZE_SUSPEND) {
-            mScheduler->disableHardwareVsync(displayId, true);
-            mScheduler->enableSyntheticVsync();
+
+        if (displayId == mActiveDisplayId) {
+            if (setSchedFifo(false) != NO_ERROR) {
+                ALOGW("Failed to set SCHED_OTHER after powering off active display: %s",
+                      strerror(errno));
+            }
+            if (setSchedAttr(false) != NO_ERROR) {
+                ALOGW("Failed set uclamp.min after powering off active display: %s",
+                      strerror(errno));
+            }
+
+            if (*currentModeOpt != hal::PowerMode::DOZE_SUSPEND) {
+                mScheduler->disableHardwareVsync(displayId, true);
+                mScheduler->enableSyntheticVsync();
+            }
         }
 
         // Make sure HWVsync is disabled before turning off the display