[Vulkan] Hardcode max possible number of Vk slots for YCbCr samplers
YCbCr samplers can take up multiple Vk descriptor slots. There is a
recommended Vulkan API for querying how many slots will be taken for a
given AHB, but it's unclear how to populate the parameters to be sure of
getting the correct answer. As the spec for that API says that the
maximum number of slots possibly taken would be the maximum number of
planes of a given format that will be sampled via YCbCr sampling, we
simply hardcode that maximum number here.
Bug: dawn:2476
Change-Id: Ie567ca7efc19fe908e2b6e9ab862ee19332820b0
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/208274
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
diff --git a/src/dawn/native/vulkan/BindGroupLayoutVk.cpp b/src/dawn/native/vulkan/BindGroupLayoutVk.cpp
index 42639ee..584674d 100644
--- a/src/dawn/native/vulkan/BindGroupLayoutVk.cpp
+++ b/src/dawn/native/vulkan/BindGroupLayoutVk.cpp
@@ -38,6 +38,7 @@
#include "dawn/native/vulkan/DescriptorSetAllocator.h"
#include "dawn/native/vulkan/DeviceVk.h"
#include "dawn/native/vulkan/FencedDeleter.h"
+#include "dawn/native/vulkan/PhysicalDeviceVk.h"
#include "dawn/native/vulkan/SamplerVk.h"
#include "dawn/native/vulkan/UtilsVulkan.h"
#include "dawn/native/vulkan/VulkanError.h"
@@ -189,8 +190,30 @@
VkDescriptorType vulkanType = VulkanDescriptorType(GetBindingInfo(bindingIndex));
+ size_t numVkDescriptors = 1;
+ if (vulkanType == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER) {
+ const BindingInfo& bindingInfo = GetBindingInfo(bindingIndex);
+ auto samplerLayout = std::get<StaticSamplerBindingInfo>(bindingInfo.bindingLayout);
+ auto sampler = ToBackend(samplerLayout.sampler);
+ if (sampler->IsYCbCr()) {
+ // A YCbCr sampler can take up multiple Vk descriptor slots. There is a
+ // recommended Vulkan API to query how many slots a YCbCr sampler should take, but
+ // it is not clear how to actually pass the Android external format to that API.
+ // However, the spec for that API says the following:
+ // "combinedImageSamplerDescriptorCount is a number between 1 and the number of
+ // planes in the format. A descriptor set layout binding with immutable Y′CBCR
+ // conversion samplers will have a maximum combinedImageSamplerDescriptorCount
+ // which is the maximum across all formats supported by its samplers of the
+ // combinedImageSamplerDescriptorCount for each format." Hence, we simply hardcode
+ // the maximum number of planes that an external format can have here. The number
+ // of overall YCbCr descriptors will be relatively small and these pools are not an
+ // overall bottleneck on memory usage.
+ numVkDescriptors = 3;
+ }
+ }
+
// absl:flat_hash_map::operator[] will return 0 if the key doesn't exist.
- descriptorCountPerType[vulkanType]++;
+ descriptorCountPerType[vulkanType] += numVkDescriptors;
}
// TODO(enga): Consider deduping allocators for layouts with the same descriptor type
