SF: parsing Detailed Timing Descriptor in the framework
The first DTD in an edid is the preferred timing which allows to get
a more precise and more often correct physical size for a display. This
can be used to estimate or correct the dpi in case the edid reports the
wrong size and hwc is not providing the right value.
See edid spec: https://glenwing.github.io/docs/VESA-EEDID-A2.pdf
Flag: com.android.graphics.surfaceflinger.flags.correct_dpi_with_display_size
Bug: 361413340
Test: DisplayIdentification_test
Test: HWComposerTest
Test: manual - see bug and doc
Change-Id: I0bb85dcf8039f923f1ac892c4a1d6bda771dbf4f
diff --git a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
index 6030427..e0753a3 100644
--- a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
@@ -166,6 +166,7 @@
expectHotplugConnect(kHwcDisplayId);
const auto info = mHwc.onHotplug(kHwcDisplayId, hal::Connection::CONNECTED);
ASSERT_TRUE(info);
+ ASSERT_TRUE(info->preferredDetailedTimingDescriptor.has_value());
EXPECT_CALL(*mHal, isVrrSupported()).WillRepeatedly(Return(false));
@@ -179,6 +180,10 @@
constexpr int32_t kHeight = 720;
constexpr int32_t kConfigGroup = 1;
constexpr int32_t kVsyncPeriod = 16666667;
+ constexpr float kMmPerInch = 25.4f;
+ const ui::Size size = info->preferredDetailedTimingDescriptor->physicalSizeInMm;
+ const float expectedDpiX = (kWidth * kMmPerInch / size.width);
+ const float expectedDpiY = (kHeight * kMmPerInch / size.height);
EXPECT_CALL(*mHal,
getDisplayAttribute(kHwcDisplayId, kConfigId, IComposerClient::Attribute::WIDTH,
@@ -218,8 +223,13 @@
EXPECT_EQ(modes.front().height, kHeight);
EXPECT_EQ(modes.front().configGroup, kConfigGroup);
EXPECT_EQ(modes.front().vsyncPeriod, kVsyncPeriod);
- EXPECT_EQ(modes.front().dpiX, -1);
- EXPECT_EQ(modes.front().dpiY, -1);
+ if (!FlagManager::getInstance().correct_dpi_with_display_size()) {
+ EXPECT_EQ(modes.front().dpiX, -1);
+ EXPECT_EQ(modes.front().dpiY, -1);
+ } else {
+ EXPECT_EQ(modes.front().dpiX, expectedDpiX);
+ EXPECT_EQ(modes.front().dpiY, expectedDpiY);
+ }
// Optional parameters are supported
constexpr int32_t kDpi = 320;
@@ -271,6 +281,10 @@
constexpr int32_t kHeight = 720;
constexpr int32_t kConfigGroup = 1;
constexpr int32_t kVsyncPeriod = 16666667;
+ constexpr float kMmPerInch = 25.4f;
+ const ui::Size size = info->preferredDetailedTimingDescriptor->physicalSizeInMm;
+ const float expectedDpiX = (kWidth * kMmPerInch / size.width);
+ const float expectedDpiY = (kHeight * kMmPerInch / size.height);
EXPECT_CALL(*mHal,
getDisplayAttribute(kHwcDisplayId, kConfigId, IComposerClient::Attribute::WIDTH,
@@ -310,8 +324,13 @@
EXPECT_EQ(modes.front().height, kHeight);
EXPECT_EQ(modes.front().configGroup, kConfigGroup);
EXPECT_EQ(modes.front().vsyncPeriod, kVsyncPeriod);
- EXPECT_EQ(modes.front().dpiX, -1);
- EXPECT_EQ(modes.front().dpiY, -1);
+ if (!FlagManager::getInstance().correct_dpi_with_display_size()) {
+ EXPECT_EQ(modes.front().dpiX, -1);
+ EXPECT_EQ(modes.front().dpiY, -1);
+ } else {
+ EXPECT_EQ(modes.front().dpiX, expectedDpiX);
+ EXPECT_EQ(modes.front().dpiY, expectedDpiY);
+ }
// Optional parameters are supported
constexpr int32_t kDpi = 320;
@@ -361,6 +380,10 @@
constexpr int32_t kHeight = 720;
constexpr int32_t kConfigGroup = 1;
constexpr int32_t kVsyncPeriod = 16666667;
+ constexpr float kMmPerInch = 25.4f;
+ const ui::Size size = info->preferredDetailedTimingDescriptor->physicalSizeInMm;
+ const float expectedDpiX = (kWidth * kMmPerInch / size.width);
+ const float expectedDpiY = (kHeight * kMmPerInch / size.height);
const hal::VrrConfig vrrConfig =
hal::VrrConfig{.minFrameIntervalNs = static_cast<Fps>(120_Hz).getPeriodNsecs(),
.notifyExpectedPresentConfig = hal::VrrConfig::
@@ -387,8 +410,13 @@
EXPECT_EQ(modes.front().configGroup, kConfigGroup);
EXPECT_EQ(modes.front().vsyncPeriod, kVsyncPeriod);
EXPECT_EQ(modes.front().vrrConfig, vrrConfig);
- EXPECT_EQ(modes.front().dpiX, -1);
- EXPECT_EQ(modes.front().dpiY, -1);
+ if (!FlagManager::getInstance().correct_dpi_with_display_size()) {
+ EXPECT_EQ(modes.front().dpiX, -1);
+ EXPECT_EQ(modes.front().dpiY, -1);
+ } else {
+ EXPECT_EQ(modes.front().dpiX, expectedDpiX);
+ EXPECT_EQ(modes.front().dpiY, expectedDpiY);
+ }
// Supports optional dpi parameter
constexpr int32_t kDpi = 320;