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author | Jamie Gennis <jgennis@google.com> | 2013-10-08 22:08:54 +0000 |
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committer | Android (Google) Code Review <android-gerrit@google.com> | 2013-10-08 22:08:54 +0000 |
commit | e652af1e808b2b15e23bc472f9be6592735a0a8e (patch) | |
tree | af6449f0770abf184ecb93c5d999ff24c1a3b854 | |
parent | 6a4d33390769d80113f16d383506dc9238e1d5fc (diff) | |
parent | 782f2ad37538c8decfbe8cac48f26c593182c358 (diff) | |
download | build-e652af1e808b2b15e23bc472f9be6592735a0a8e.tar.gz |
Merge "BoardConfig: Add and document vsync phase offset setting" into klp-dev
-rw-r--r-- | target/board/generic/BoardConfig.mk | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk index 3bd4f31079..60decfb3e4 100644 --- a/target/board/generic/BoardConfig.mk +++ b/target/board/generic/BoardConfig.mk @@ -45,6 +45,28 @@ BUILD_EMULATOR_OPENGL := true # the GLES renderer disables itself if host GL acceleration isn't available. USE_OPENGL_RENDERER := true +# Set the phase offset of the system's vsync event relative to the hardware +# vsync. The system's vsync event drives Choreographer and SurfaceFlinger's +# rendering. This value is the number of nanoseconds after the hardware vsync +# that the system vsync event will occur. +# +# This phase offset allows adjustment of the minimum latency from application +# wake-up (by Choregographer) time to the time at which the resulting window +# image is displayed. This value may be either positive (after the HW vsync) +# or negative (before the HW vsync). Setting it to 0 will result in a +# minimum latency of two vsync periods because the app and SurfaceFlinger +# will run just after the HW vsync. Setting it to a positive number will +# result in the minimum latency being: +# +# (2 * VSYNC_PERIOD - (vsyncPhaseOffsetNs % VSYNC_PERIOD)) +# +# Note that reducing this latency makes it more likely for the applications +# to not have their window content image ready in time. When this happens +# the latency will end up being an additional vsync period, and animations +# will hiccup. Therefore, this latency should be tuned somewhat +# conservatively (or at least with awareness of the trade-off being made). +VSYNC_EVENT_PHASE_OFFSET_NS := 0 + TARGET_USERIMAGES_USE_EXT4 := true BOARD_SYSTEMIMAGE_PARTITION_SIZE := 576716800 BOARD_USERDATAIMAGE_PARTITION_SIZE := 209715200 |