SF: Hash and cache descriptor block serial number
More EDID fields are required as a part of migrating to EDID-based
display IDs. This CL parses the device's serial number from the serial
number descriptor bloc, (depicted by the FF marker), hashes it using a
stable hash, and serves it as a part of the Edid struct.
Later, amongst others, this value will be used to fabricate a unique
display ID that is based on the display's EDID.
See:
1. EDID spec: https://glenwing.github.io/docs/VESA-EEDID-A2.pdf
2. https://en.wikipedia.org/wiki/Extended_Display_Identification_Data#Structure,_version_1.4
Flag: com.android.graphics.surfaceflinger.flags.stable_edid_ids
Bug: 378923759
Test: DisplayIdentification_test
Change-Id: If9c9358b0d0850337496740d15419fd0ed330a02
diff --git a/libs/ui/DisplayIdentification.cpp b/libs/ui/DisplayIdentification.cpp
index 5cdaa71..8d6f74b 100644
--- a/libs/ui/DisplayIdentification.cpp
+++ b/libs/ui/DisplayIdentification.cpp
@@ -249,7 +249,8 @@
view = view.subspan(kDescriptorOffset);
std::string_view displayName;
- std::string_view serialNumber;
+ std::string_view descriptorBlockSerialNumber;
+ std::optional<uint64_t> hashedDescriptorBlockSNOpt = std::nullopt;
std::string_view asciiText;
ui::Size preferredDTDPixelSize;
ui::Size preferredDTDPhysicalSize;
@@ -274,7 +275,10 @@
asciiText = parseEdidText(descriptor);
break;
case 0xff:
- serialNumber = parseEdidText(descriptor);
+ descriptorBlockSerialNumber = parseEdidText(descriptor);
+ hashedDescriptorBlockSNOpt = descriptorBlockSerialNumber.empty()
+ ? std::nullopt
+ : ftl::stable_hash(descriptorBlockSerialNumber);
break;
}
} else if (isDetailedTimingDescriptor(view)) {
@@ -315,7 +319,7 @@
if (modelString.empty()) {
ALOGW("Invalid EDID: falling back to serial number due to missing display name.");
- modelString = serialNumber;
+ modelString = descriptorBlockSerialNumber;
}
if (modelString.empty()) {
ALOGW("Invalid EDID: falling back to ASCII text due to missing serial number.");
@@ -369,6 +373,7 @@
.manufacturerId = manufacturerId,
.productId = productId,
.hashedBlockZeroSerialNumberOpt = hashedBlockZeroSNOpt,
+ .hashedDescriptorBlockSerialNumberOpt = hashedDescriptorBlockSNOpt,
.pnpId = *pnpId,
.modelHash = modelHash,
.displayName = displayName,
diff --git a/libs/ui/include/ui/DisplayIdentification.h b/libs/ui/include/ui/DisplayIdentification.h
index 85e5cee..cf67d7b 100644
--- a/libs/ui/include/ui/DisplayIdentification.h
+++ b/libs/ui/include/ui/DisplayIdentification.h
@@ -70,6 +70,7 @@
uint16_t manufacturerId;
uint16_t productId;
std::optional<uint64_t> hashedBlockZeroSerialNumberOpt;
+ std::optional<uint64_t> hashedDescriptorBlockSerialNumberOpt;
PnpId pnpId;
uint32_t modelHash;
std::string_view displayName;
diff --git a/libs/ui/tests/DisplayIdentification_test.cpp b/libs/ui/tests/DisplayIdentification_test.cpp
index fbbe719..d1699e7 100644
--- a/libs/ui/tests/DisplayIdentification_test.cpp
+++ b/libs/ui/tests/DisplayIdentification_test.cpp
@@ -193,6 +193,7 @@
EXPECT_EQ(12610, edid->productId);
EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());
EXPECT_EQ(ftl::stable_hash("12345678"), edid->hashedBlockZeroSerialNumberOpt.value());
+ EXPECT_FALSE(edid->hashedDescriptorBlockSerialNumberOpt.has_value());
EXPECT_EQ(21, edid->manufactureOrModelYear);
EXPECT_EQ(0, edid->manufactureWeek);
EXPECT_EQ(26, edid->physicalSizeInCm.width);
@@ -213,6 +214,8 @@
EXPECT_EQ(10348, edid->productId);
EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());
EXPECT_EQ(ftl::stable_hash("16843009"), edid->hashedBlockZeroSerialNumberOpt.value());
+ EXPECT_TRUE(edid->hashedDescriptorBlockSerialNumberOpt.has_value());
+ EXPECT_EQ(ftl::stable_hash("CN4202137Q"), edid->hashedDescriptorBlockSerialNumberOpt.value());
EXPECT_EQ(22, edid->manufactureOrModelYear);
EXPECT_EQ(2, edid->manufactureWeek);
EXPECT_EQ(64, edid->physicalSizeInCm.width);
@@ -233,6 +236,7 @@
EXPECT_EQ(2302, edid->productId);
EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());
EXPECT_EQ(ftl::stable_hash("87654321"), edid->hashedBlockZeroSerialNumberOpt.value());
+ EXPECT_FALSE(edid->hashedDescriptorBlockSerialNumberOpt.has_value());
EXPECT_EQ(21, edid->manufactureOrModelYear);
EXPECT_EQ(41, edid->manufactureWeek);
EXPECT_EQ(16, edid->physicalSizeInCm.width);
@@ -259,6 +263,7 @@
EXPECT_EQ(41622, edid->productId);
EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());
EXPECT_EQ(ftl::stable_hash("16843009"), edid->hashedBlockZeroSerialNumberOpt.value());
+ EXPECT_FALSE(edid->hashedDescriptorBlockSerialNumberOpt.has_value());
EXPECT_EQ(29, edid->manufactureOrModelYear);
EXPECT_EQ(0, edid->manufactureWeek);
EXPECT_EQ(128, edid->physicalSizeInCm.width);
@@ -284,6 +289,7 @@
EXPECT_EQ("Hisense", edid->displayName);
EXPECT_EQ(0, edid->productId);
EXPECT_FALSE(edid->hashedBlockZeroSerialNumberOpt.has_value());
+ EXPECT_FALSE(edid->hashedDescriptorBlockSerialNumberOpt.has_value());
EXPECT_EQ(29, edid->manufactureOrModelYear);
EXPECT_EQ(18, edid->manufactureWeek);
EXPECT_EQ(0, edid->physicalSizeInCm.width);
@@ -310,6 +316,7 @@
EXPECT_EQ(9373, edid->productId);
EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());
EXPECT_EQ(ftl::stable_hash("11223344"), edid->hashedBlockZeroSerialNumberOpt.value());
+ EXPECT_FALSE(edid->hashedDescriptorBlockSerialNumberOpt.has_value());
EXPECT_EQ(23, edid->manufactureOrModelYear);
EXPECT_EQ(0xff, edid->manufactureWeek);
EXPECT_EQ(52, edid->physicalSizeInCm.width);