vulkan: treat RADV like the other AMD drivers for unbound sparse images

Add EDEN_NX2_SPARSE_UNBACKED=0/1 to force unbound sparse images off or on
on any driver, so Linux AMD testers can check whether RADV needs this.

1 files changed, 12 insertions, 2 deletions

diff --git a/src/video_core/vulkan_common/vulkan_device.h b/src/video_core/vulkan_common/vulkan_device.h
index 3d2408fc35..8237868c6d 100644
--- a/src/video_core/vulkan_common/vulkan_device.h
+++ b/src/video_core/vulkan_common/vulkan_device.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <atomic>
+#include <cstdlib>
 #include <optional>
 #include <set>
 #include <span>
@@ -333,10 +334,19 @@ public:
 
     /// Whether images with no memory bound may be sampled and used as attachments. AMD's drivers
     /// fault on it (the GPU hangs shortly after the first such draw), so large images there are
-    /// backed normally.
+    /// backed normally. RADV is counted in until someone shows it doesn't need it.
+    /// EDEN_NX2_SPARSE_UNBACKED=1 allows unbound images on any driver, =0 on none.
     bool CanUseUnbackedSparseImages() const {
+        static const char forced = [] {
+            const char* value = std::getenv("EDEN_NX2_SPARSE_UNBACKED");
+            return value == nullptr ? '\0' : value[0];
+        }();
+        if (forced == '0' || forced == '1') {
+            return forced == '1';
+        }
         const VkDriverIdKHR id = GetDriverID();
-        return id != VK_DRIVER_ID_AMD_PROPRIETARY && id != VK_DRIVER_ID_AMD_OPEN_SOURCE;
+        return id != VK_DRIVER_ID_AMD_PROPRIETARY && id != VK_DRIVER_ID_AMD_OPEN_SOURCE &&
+               id != VK_DRIVER_ID_MESA_RADV;
     }
 
     /// Returns true for tile-based deferred renderers.