D3D12: Hard-enable D3D12SplitBufferTextureCopyForRowsPerImagePaddings

The toggle `D3D12SplitBufferTextureCopyForRowsPerImagePaddings` doesn't
need to be defined as the code path it controlled before should always
be executed. It is because:
1. In D3D12, the concept of `bufferLocation` specifies how to treat a
   region of a buffer as a texture. In buffer-texture copies
   `rowsPerImage` is used as the height of the `bufferLocation`, so if
   the buffer is not large enough to hold a complete `rowsPerImage`
   D3D12 debug layer will generate an error that the buffer is not large
   enough to hold a complete `bufferLocation`, which fully meets the
   concept in D3D12 and cannot say it a `bug` of D3D12 runtime.
2. Although `UnrestrictedBufferTextureCopyPitchSupported` has been used
   in Dawn we still need to split a buffer-texture copy into two in
   some certain situations because of (1).

Bug: 42240278
Change-Id: I83981d92057b79661aa39ede66a611329b7cf8a4
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/218915
Commit-Queue: Jiawei Shao <[email protected]>
Reviewed-by: Kai Ninomiya <[email protected]>
Reviewed-by: Loko Kung <[email protected]>

src/dawn/native/Toggles.cpp

@@ -265,14 +265,6 @@ static constexpr ToggleEnumAndInfoList kToggleNameAndInfoList = {{
       "Initialize workgroup memory with OpConstantNull on Vulkan when the Vulkan extension "
       "VK_KHR_zero_initialize_workgroup_memory is supported.",
       "https://crbug.com/dawn/1302", ToggleStage::Device}},
-    {Toggle::D3D12SplitBufferTextureCopyForRowsPerImagePaddings,
-     {"d3d12_split_buffer_texture_copy_for_rows_per_image_paddings",
-      "D3D12 requires more buffer storage than it should when rowsPerImage is greater than "
-      "copyHeight, which means there are pure padding row(s) on each image. In this situation, "
-      "the buffer used for B2T/T2B copy might be big enough according to WebGPU's spec but it "
-      "doesn't meet D3D12's requirement, then we need to workaround it via split the copy "
-      "operation into two copies, in order to make B2T/T2B copy being done correctly on D3D12.",
-      "https://crbug.com/dawn/1289", ToggleStage::Device}},
     {Toggle::MetalRenderR8RG8UnormSmallMipToTempTexture,
      {"metal_render_r8_rg8_unorm_small_mip_to_temp_texture",
       "Metal Intel devices have issues with r8unorm and rg8unorm textures where rendering to small "

src/dawn/native/Toggles.h

@@ -83,7 +83,6 @@ enum class Toggle {
     TimestampQuantization,
     ClearBufferBeforeResolveQueries,
     VulkanUseZeroInitializeWorkgroupMemoryExtension,
-    D3D12SplitBufferTextureCopyForRowsPerImagePaddings,
     MetalRenderR8RG8UnormSmallMipToTempTexture,
     DisableBlobCache,
     D3D12ForceClearCopyableDepthStencilTextureOnCreation,

src/dawn/native/d3d12/PhysicalDeviceD3D12.cpp

@@ -702,13 +702,6 @@ void PhysicalDevice::SetupBackendDeviceToggles(dawn::platform::Platform* platfor
         deviceToggles->Default(Toggle::D3D12DontSetClearValueOnDepthTextureCreation, true);
     }
 
-    // Currently this workaround is needed on any D3D12 backend for some particular situations.
-    // But we may need to limit it if D3D12 runtime fixes the bug on its new release. See
-    // https://crbug.com/dawn/1289 for more information.
-    // TODO(dawn:1289): Unset this toggle when we skip the split on the buffer-texture copy
-    // on the platforms where UnrestrictedBufferTextureCopyPitchSupported is true.
-    deviceToggles->Default(Toggle::D3D12SplitBufferTextureCopyForRowsPerImagePaddings, true);
-
     // This workaround is only needed on Intel Gen12LP with driver prior to 30.0.101.1692.
     // See http://crbug.com/dawn/949 for more information.
     if (gpu_info::IsIntelGen12LP(vendorId, deviceId)) {

src/dawn/native/d3d12/UtilsD3D12.cpp

@@ -68,9 +68,8 @@ uint64_t RequiredCopySizeByD3D12(const uint32_t bytesPerRow,
     return requiredCopySizeByD3D12;
 }
 
-// This function is used to access whether we need a workaround for D3D12's wrong algorithm
-// of calculating required buffer size for B2T/T2B copy. The workaround is needed only when
-//   - The corresponding toggle is enabled.
+// This function is used to access whether we need a workaround for D3D12's algorithm of
+// calculating required buffer size for B2T/T2B copy. The workaround is needed only when
 //   - It is a 3D texture (so the format is uncompressed).
 //   - There are multiple depth images to be copied (copySize.depthOrArrayLayers > 1).
 //   - It has rowsPerImage paddings (rowsPerImage > copySize.height).
@@ -79,10 +78,7 @@ bool NeedBufferSizeWorkaroundForBufferTextureCopyOnD3D12(const BufferCopy& buffe
                                                          const TextureCopy& textureCopy,
                                                          const Extent3D& copySize) {
     TextureBase* texture = textureCopy.texture.Get();
-    Device* device = ToBackend(texture->GetDevice());
-
-    if (!device->IsToggleEnabled(Toggle::D3D12SplitBufferTextureCopyForRowsPerImagePaddings) ||
-        texture->GetDimension() != wgpu::TextureDimension::e3D ||
+    if (texture->GetDimension() != wgpu::TextureDimension::e3D ||
         copySize.depthOrArrayLayers <= 1 || bufferCopy.rowsPerImage <= copySize.height) {
         return false;
     }

src/dawn/tests/end2end/RequiredBufferSizeInCopyTests.cpp

@@ -211,15 +211,13 @@ TEST_P(RequiredBufferSizeInCopyTests, MinimumBufferSize) {
     DoTest(size, copySize, rowsPerImage);
 }
 
-DAWN_INSTANTIATE_TEST_P(
-    RequiredBufferSizeInCopyTests,
-    {D3D11Backend(), D3D12Backend(),
-     D3D12Backend({"d3d12_split_buffer_texture_copy_for_rows_per_image_paddings"}), MetalBackend(),
-     OpenGLBackend(), OpenGLESBackend(), VulkanBackend()},
-    {Type::T2BCopy, Type::B2TCopy},
-    {wgpu::TextureDimension::e3D, wgpu::TextureDimension::e2D},
-    {2u, 1u},
-    {1u, 0u});
+DAWN_INSTANTIATE_TEST_P(RequiredBufferSizeInCopyTests,
+                        {D3D11Backend(), D3D12Backend(), MetalBackend(), OpenGLBackend(),
+                         OpenGLESBackend(), VulkanBackend()},
+                        {Type::T2BCopy, Type::B2TCopy},
+                        {wgpu::TextureDimension::e3D, wgpu::TextureDimension::e2D},
+                        {2u, 1u},
+                        {1u, 0u});
 
 }  // anonymous namespace
 }  // namespace dawn