[TEST] Late catch on accelerated image upload path

src/video_core/renderer_vulkan/vk_compute_pass.cpp

@@ -746,10 +746,8 @@ void BlockLinearUnswizzle3DPass::Unswizzle(
 
     const u32 MAX_BATCH_SLICES = (std::min)(z_count, image.info.size.depth);
 
-    if (!image.has_compute_unswizzle_buffer) {
-        // Allocate exactly what this batch needs
-        image.AllocateComputeUnswizzleBuffer(MAX_BATCH_SLICES);
-    }
+    // Allocate or grow to cover this batch's slice count
+    image.AllocateComputeUnswizzleBuffer(MAX_BATCH_SLICES);
 
     ASSERT(swizzles.size() == 1);
     const auto& sw = swizzles[0];

src/video_core/renderer_vulkan/vk_texture_cache.cpp

@@ -1635,9 +1635,6 @@ Image::Image(const VideoCommon::NullImageParams& params) : VideoCommon::ImageBas
 Image::~Image() = default;
 
 void Image::AllocateComputeUnswizzleBuffer(u32 max_slices) {
-    if (has_compute_unswizzle_buffer)
-        return;
-
     using VideoCore::Surface::BytesPerBlock;
 
     const u32 block_bytes  = BytesPerBlock(info.format); // 8 for BC1, 16 for BC6H
@@ -1654,7 +1651,12 @@ void Image::AllocateComputeUnswizzleBuffer(u32 max_slices) {
         static_cast<u64>(blocks_y) *
         static_cast<u64>(blocks_z);
 
-    compute_unswizzle_buffer_size = block_count * block_bytes;
+    const VkDeviceSize required_size = block_count * block_bytes;
+    if (has_compute_unswizzle_buffer && required_size <= compute_unswizzle_buffer_size) {
+        return;
+    }
+
+    compute_unswizzle_buffer_size = required_size;
 
     VkBufferCreateInfo ci{
         .sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,