commit 8d0a0c43c1416e8540b0adf527be2ec5c69cccff
author Lucas Berthou <berlu@google.com> Tue Aug 27 14:32:31 2024 +0000
committer Lucas Berthou <berlu@google.com> Thu Sep 12 15:34:14 2024 +0000
tree 682fb7f95b794e517bc233658a1138930bae3728
parent 5b0bdd2cd9b9920679fd530b8b136559d5441343

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

services/surfaceflinger/DisplayHardware/HWComposer.h

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index dec4bfe..b95c619 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -134,7 +134,8 @@
     // supported by the HWC can be queried in advance, but allocation may fail for other reasons.
     virtual bool allocateVirtualDisplay(HalVirtualDisplayId, ui::Size, ui::PixelFormat*) = 0;
 
-    virtual void allocatePhysicalDisplay(hal::HWDisplayId, PhysicalDisplayId) = 0;
+    virtual void allocatePhysicalDisplay(hal::HWDisplayId, PhysicalDisplayId,
+                                         std::optional<ui::Size> physicalSize) = 0;
 
     // Attempts to create a new layer on this display
     virtual std::shared_ptr<HWC2::Layer> createLayer(HalDisplayId) = 0;
@@ -349,7 +350,8 @@
     bool allocateVirtualDisplay(HalVirtualDisplayId, ui::Size, ui::PixelFormat*) override;
 
     // Called from SurfaceFlinger, when the state for a new physical display needs to be recreated.
-    void allocatePhysicalDisplay(hal::HWDisplayId, PhysicalDisplayId) override;
+    void allocatePhysicalDisplay(hal::HWDisplayId, PhysicalDisplayId,
+                                 std::optional<ui::Size> physicalSize) override;
 
     // Attempts to create a new layer on this display
     std::shared_ptr<HWC2::Layer> createLayer(HalDisplayId) override;
@@ -532,6 +534,13 @@
     std::optional<DisplayIdentificationInfo> onHotplugDisconnect(hal::HWDisplayId);
     bool shouldIgnoreHotplugConnect(hal::HWDisplayId, bool hasDisplayIdentificationData) const;
 
+    aidl::android::hardware::graphics::composer3::DisplayConfiguration::Dpi
+    getEstimatedDotsPerInchFromSize(uint64_t hwcDisplayId, const HWCDisplayMode& hwcMode) const;
+
+    aidl::android::hardware::graphics::composer3::DisplayConfiguration::Dpi correctedDpiIfneeded(
+            aidl::android::hardware::graphics::composer3::DisplayConfiguration::Dpi dpi,
+            aidl::android::hardware::graphics::composer3::DisplayConfiguration::Dpi estimatedDpi)
+            const;
     std::vector<HWCDisplayMode> getModesFromDisplayConfigurations(uint64_t hwcDisplayId,
                                                                   int32_t maxFrameIntervalNs) const;
     std::vector<HWCDisplayMode> getModesFromLegacyDisplayConfigs(uint64_t hwcDisplayId) const;