From b23f6fdc1d039906abc229c1997cc320e25913b7 Mon Sep 17 00:00:00 2001
From: squidbus <175574877+squidbus@users.noreply.github.com>
Date: Mon, 12 May 2025 15:27:47 -0700
Subject: [PATCH] buffer_cache: Split updateBuffer calls into 65536 byte
 chunks. (#2915)

---
 src/video_core/buffer_cache/buffer_cache.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/video_core/buffer_cache/buffer_cache.cpp b/src/video_core/buffer_cache/buffer_cache.cpp
index fb9fd755e..c993ef3e5 100644
--- a/src/video_core/buffer_cache/buffer_cache.cpp
+++ b/src/video_core/buffer_cache/buffer_cache.cpp
@@ -238,7 +238,15 @@ void BufferCache::InlineData(VAddr address, const void* value, u32 num_bytes, bo
         .bufferMemoryBarrierCount = 1,
         .pBufferMemoryBarriers = &pre_barrier,
     });
-    cmdbuf.updateBuffer(buffer->Handle(), buffer->Offset(address), num_bytes, value);
+    // vkCmdUpdateBuffer can only copy up to 65536 bytes at a time.
+    static constexpr u32 UpdateBufferMaxSize = 65536;
+    const auto dst_offset = buffer->Offset(address);
+    for (u32 offset = 0; offset < num_bytes; offset += UpdateBufferMaxSize) {
+        const auto* update_src = static_cast<const u8*>(value) + offset;
+        const auto update_dst = dst_offset + offset;
+        const auto update_size = std::min(num_bytes - offset, UpdateBufferMaxSize);
+        cmdbuf.updateBuffer(buffer->Handle(), update_dst, update_size, update_src);
+    }
     cmdbuf.pipelineBarrier2(vk::DependencyInfo{
         .dependencyFlags = vk::DependencyFlagBits::eByRegion,
         .bufferMemoryBarrierCount = 1,