Disable multiple mip levels for r8/rg8unorm textures on Metal

Bug: dawn:1071
Change-Id: I2cc9173f0dff325e4bb2583bb27a98bbaaa61531
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/63462
Commit-Queue: Brandon Jones <bajones@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

src/dawn_native/Texture.cpp

@@ -311,6 +311,14 @@ namespace dawn_native {
                 "disabled on Metal.");
         }
 
+        if (device->IsToggleEnabled(Toggle::DisableR8RG8Mipmaps) && descriptor->mipLevelCount > 1 &&
+            (descriptor->format == wgpu::TextureFormat::R8Unorm ||
+             descriptor->format == wgpu::TextureFormat::RG8Unorm)) {
+            return DAWN_VALIDATION_ERROR(
+                "https://crbug.com/dawn/1071: r8unorm and rg8unorm textures with more than one mip "
+                "level are disabled on Metal.");
+        }
+
         return {};
     }
 

src/dawn_native/Toggles.cpp

@@ -217,6 +217,11 @@ namespace dawn_native {
               "Enables calls to SetLabel to be forwarded to backend-specific APIs that label "
               "objects.",
               "https://crbug.com/dawn/840"}},
+            {Toggle::DisableR8RG8Mipmaps,
+             {"disable_r8_rg8_mipmaps",
+              "Disables mipmaps for r8unorm and rg8unorm textures, which are known on some drivers "
+              "to not clear correctly.",
+              "https://crbug.com/dawn/1071"}},
             // Dummy comment to separate the }} so it is clearer what to copy-paste to add a toggle.
         }};
     }  // anonymous namespace

src/dawn_native/Toggles.h

@@ -59,6 +59,7 @@ namespace dawn_native {
         DisableWorkgroupInit,
         DisableSymbolRenaming,
         UseUserDefinedLabelsInBackend,
+        DisableR8RG8Mipmaps,
 
         EnumCount,
         InvalidEnum = EnumCount,

src/dawn_native/metal/DeviceMTL.mm

@@ -199,13 +199,21 @@ namespace dawn_native { namespace metal {
         // TODO(crbug.com/dawn/846): tighten this workaround when the driver bug is fixed.
         SetToggle(Toggle::AlwaysResolveIntoZeroLevelAndLayer, true);
 
+        const PCIInfo& pciInfo = GetAdapter()->GetPCIInfo();
+
         // TODO(crbug.com/dawn/847): Use MTLStorageModeShared instead of MTLStorageModePrivate when
         // creating MTLCounterSampleBuffer in QuerySet on Intel platforms, otherwise it fails to
         // create the buffer. Change to use MTLStorageModePrivate when the bug is fixed.
         if (@available(macOS 10.15, iOS 14.0, *)) {
-            bool useSharedMode = gpu_info::IsIntel(this->GetAdapter()->GetPCIInfo().vendorId);
+            bool useSharedMode = gpu_info::IsIntel(pciInfo.vendorId);
             SetToggle(Toggle::MetalUseSharedModeForCounterSampleBuffer, useSharedMode);
         }
+
+        // TODO(crbug.com/dawn/1071): r8unorm and rg8unorm textures with multiple mip levels don't
+        // clear properly on Intel Macs.
+        if (gpu_info::IsIntel(pciInfo.vendorId)) {
+            SetToggle(Toggle::DisableR8RG8Mipmaps, true);
+        }
     }
 
     ResultOrError<Ref<BindGroupBase>> Device::CreateBindGroupImpl(

src/tests/end2end/CopyTests.cpp

@@ -2120,6 +2120,11 @@ TEST_P(CopyTests_T2T, CopyFromNonZeroMipLevelWithTexelBlockSizeLessThan4Bytes) {
             continue;
         }
 
+        if (HasToggleEnabled("disable_r8_rg8_mipmaps") &&
+            (format == wgpu::TextureFormat::R8Unorm || format == wgpu::TextureFormat::RG8Unorm)) {
+            continue;
+        }
+
         for (uint32_t textureLayer : kTestTextureLayer) {
             const wgpu::Extent3D kUploadSize = {4u, 4u, textureLayer};
 

src/tests/end2end/NonzeroTextureCreationTests.cpp

@@ -104,6 +104,12 @@ namespace {
                  GetParam().mFormat == wgpu::TextureFormat::Depth24PlusStencil8) &&
                 IsMetal() && IsIntel() && GetParam().mMip != 0);
 
+            // TODO(crbug.com/dawn/1071): Implement a workaround on Intel/Metal backends.
+            DAWN_SUPPRESS_TEST_IF((GetParam().mFormat == wgpu::TextureFormat::R8Unorm ||
+                                   GetParam().mFormat == wgpu::TextureFormat::RG8Unorm) &&
+                                  GetParam().mMipCount > 1 &&
+                                  HasToggleEnabled("disable_r8_rg8_mipmaps"));
+
             // Copies from depth textures not fully supported on the OpenGL backend right now.
             DAWN_SUPPRESS_TEST_IF(GetParam().mFormat == wgpu::TextureFormat::Depth32Float &&
                                   (IsOpenGL() || IsOpenGLES()));