commit f9d4e44fff4f9c0a09e5820a5596c6dec34ee4da
author Tim Murray <timmurray@google.com> Tue Aug 02 15:43:59 2016 -0700
committer Tim Murray <timmurray@google.com> Tue Aug 02 16:58:47 2016 -0700
tree b903f62ea48f2d2f7be6e8879779355135d808f7
parent acff43dca6a3c8a29f449706967d4de21c373d26

Disable SCHED_FIFO when turning off the display.

There can be long SF runtimes when turning the display on or off. Only
use SCHED_FIFO when we are actively going to be rendering frames, not
when turning the display on or off.

bug 30375418

Change-Id: Ibef8e5f3bba0bafc36f92f9f1b299f015fc335f9

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index a36a8cd..820c332 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2613,6 +2613,7 @@
     }
 
     if (currentMode == HWC_POWER_MODE_OFF) {
+        // Turn on the display
         getHwComposer().setPowerMode(type, mode);
         if (type == DisplayDevice::DISPLAY_PRIMARY) {
             // FIXME: eventthread only knows about the main display right now
@@ -2623,7 +2624,19 @@
         mVisibleRegionsDirty = true;
         mHasPoweredOff = true;
         repaintEverything();
+
+        struct sched_param param = {0};
+        param.sched_priority = 1;
+        if (sched_setscheduler(0, SCHED_FIFO, &param) != 0) {
+            ALOGW("Couldn't set SCHED_FIFO on display on");
+        }
     } else if (mode == HWC_POWER_MODE_OFF) {
+        // Turn off the display
+        struct sched_param param = {0};
+        if (sched_setscheduler(0, SCHED_OTHER, &param) != 0) {
+            ALOGW("Couldn't set SCHED_OTHER on display off");
+        }
+
         if (type == DisplayDevice::DISPLAY_PRIMARY) {
             disableHardwareVsync(true); // also cancels any in-progress resync