Add informational toggle that sample mask is broken on Mac Intel

Bug: dawn:1462
Change-Id: Ifec68914edb7d0f7eaf90e066491a0af3fe7b232
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/114400
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/dawn/native/Toggles.cpp

@@ -332,6 +332,12 @@ static constexpr ToggleEnumAndInfoList kToggleNameAndInfoList = {{
       "This toggle is off by default. It is expected to turn on or get removed when WebGPU V1 "
       "ships and stays stable.",
       "https://crbug.com/dawn/1563"}},
+    {Toggle::NoWorkaroundSampleMaskBecomesZeroForAllButLastColorTarget,
+     {"no_workaround_sample_mask_becomes_zero_for_all_but_last_color_target",
+      "MacOS 12.0+ Intel has a bug where the sample mask is only applied for the last color "
+      "target. If there are multiple color targets, all but the last one will use a sample mask "
+      "of zero.",
+      "https://crbug.com/dawn/1462"}}
     // Comment to separate the }} so it is clearer what to copy-paste to add a toggle.
 }};
 }  // anonymous namespace

src/dawn/native/Toggles.h

@@ -84,6 +84,9 @@ enum class Toggle {
     D3D12Allocate2DTexturewithCopyDstAsCommittedResource,
     DisallowDeprecatedAPIs,
 
+    // Unresolved issues.
+    NoWorkaroundSampleMaskBecomesZeroForAllButLastColorTarget,
+
     EnumCount,
     InvalidEnum = EnumCount,
 };

src/dawn/native/metal/DeviceMTL.mm

@@ -257,6 +257,15 @@ void Device::InitTogglesFromDriver() {
     if (@available(macos 11.0, iOS 14.0, *)) {
         SetToggle(Toggle::MetalUseMockBlitEncoderForWriteTimestamp, true);
     }
+
+#if DAWN_PLATFORM_IS(MACOS)
+    if (gpu_info::IsIntel(vendorId)) {
+        if ([NSProcessInfo.processInfo
+                isOperatingSystemAtLeastVersion:NSOperatingSystemVersion{12, 0, 0}]) {
+            ForceSetToggle(Toggle::NoWorkaroundSampleMaskBecomesZeroForAllButLastColorTarget, true);
+        }
+    }
+#endif
 }
 
 ResultOrError<Ref<BindGroupBase>> Device::CreateBindGroupImpl(

src/dawn/tests/end2end/MultisampledRenderingTests.cpp

@@ -643,9 +643,6 @@ TEST_P(MultisampledRenderingTest, ResolveInto2DTextureWithEmptyFinalSampleMask)
 // Test doing MSAA resolve into multiple resolve targets works correctly with a non-default sample
 // mask.
 TEST_P(MultisampledRenderingTest, ResolveIntoMultipleResolveTargetsWithSampleMask) {
-    // TODO(crbug.com/dawn/1462): Re-enable on Mac Intel 12.4.
-    DAWN_SUPPRESS_TEST_IF(IsMetal() && IsIntel() && (IsMacOS(12, 4) || IsMacOS(12, 5)));
-
     // TODO(dawn:1550) Fails on ARM-based Android devices.
     DAWN_SUPPRESS_TEST_IF(IsAndroid() && IsARM());
 
@@ -682,7 +679,13 @@ TEST_P(MultisampledRenderingTest, ResolveIntoMultipleResolveTargetsWithSampleMas
     wgpu::CommandBuffer commandBuffer = commandEncoder.Finish();
     queue.Submit(1, &commandBuffer);
 
-    VerifyResolveTarget(kRed, mResolveTexture, 0, 0, kMSAACoverage);
+    // TODO(crbug.com/dawn/1462): Work around that a sample mask of zero is used for all
+    // color targets except the last one.
+    VerifyResolveTarget(
+        HasToggleEnabled("no_workaround_sample_mask_becomes_zero_for_all_but_last_color_target")
+            ? wgpu::Color{}
+            : kRed,
+        mResolveTexture, 0, 0, kMSAACoverage);
     VerifyResolveTarget(kGreen, resolveTexture2, 0, 0, kMSAACoverage);
 }
 
@@ -812,9 +815,6 @@ TEST_P(MultisampledRenderingTest, ResolveIntoMultipleResolveTargetsWithShaderOut
     // supported on some platforms.
     DAWN_TEST_UNSUPPORTED_IF(HasToggleEnabled("disable_sample_variables"));
 
-    // TODO(crbug.com/dawn/1462): Re-enable on Mac Intel 12.4.
-    DAWN_SUPPRESS_TEST_IF(IsMetal() && IsIntel() && (IsMacOS(12, 4) || IsMacOS(12, 5)));
-
     wgpu::TextureView multisampledColorView2 =
         CreateTextureForRenderAttachment(kColorFormat, kSampleCount).CreateView();
     wgpu::Texture resolveTexture2 = CreateTextureForRenderAttachment(kColorFormat, 1);
@@ -866,7 +866,13 @@ TEST_P(MultisampledRenderingTest, ResolveIntoMultipleResolveTargetsWithShaderOut
     wgpu::CommandBuffer commandBuffer = commandEncoder.Finish();
     queue.Submit(1, &commandBuffer);
 
-    VerifyResolveTarget(kRed, mResolveTexture, 0, 0, kMSAACoverage);
+    // TODO(crbug.com/dawn/1462): Work around that a sample mask of zero is used for all
+    // color targets except the last one.
+    VerifyResolveTarget(
+        HasToggleEnabled("no_workaround_sample_mask_becomes_zero_for_all_but_last_color_target")
+            ? wgpu::Color{}
+            : kRed,
+        mResolveTexture, 0, 0, kMSAACoverage);
     VerifyResolveTarget(kGreen, resolveTexture2, 0, 0, kMSAACoverage);
 }