fix(android): fall back to stock Vulkan driver on Adreno 8xx (Snapdragon 8 Elite / S25-S26) - #24
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The bundled Turnip driver (vulkan.ad07xx.so) only supports Adreno 6xx/7xx and enumerates zero physical devices on an Adreno 840 (Snapdragon 8 Elite Gen 5, Galaxy S25/S26). DXVK then throws DxvkInstance::enumAdapters: Failed to enumerate adapters and the app dies at TheDisplay->init(). The stock Qualcomm driver on Adreno 8xx already exposes Vulkan 1.3 and textureCompressionBC, so Turnip is neither needed nor usable there (this is the 'rung 1' path from the renderer-research doc). Parse the Adreno model number from /sys/class/kgsl/kgsl-3d0/gpu_model and, for series >= 8, skip staging the Turnip driver and setting the adrenotools env vars so the DXVK loader (vulkan_loader.cpp) falls through to the stock libvulkan.so. GENERALSX_NO_TURNIP=1 forces the same path on any device (useful for debugging or for a8xx parts the sysfs parse doesn't recognise). Tested on Galaxy S26+ (Adreno 840): boots to the main menu and plays a skirmish at ~30 FPS where the stock build crashed on launch. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This was referenced Sep 1, 2026
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Problem
On an Adreno 840 (Snapdragon 8 Elite Gen 5 — Galaxy S26 / S26+ Ultra, and the same applies to Adreno 830 / 8 Elite on S25), the app dies on launch:
The bundled Turnip package is
vulkan.ad07xx.so— an Adreno 6xx/7xx build. It loads on an a8xx part but enumerates zero physical devices, soDxvkInstancethrows andTheDisplay->init()aborts.Per
ANDROID_RENDERER_RESEARCH_2026-07.md§5, Adreno 8xx is explicitly thestock-driverrung: the stock Qualcomm driver on a8xx already reports Vulkan 1.3 andtextureCompressionBC, so Turnip is neither needed nor usable there. That fallback just isn't wired up yet.Fix
gxAdrenoSeries()reads/sys/class/kgsl/kgsl-3d0/gpu_model(e.g.Adreno840v2acd) and parses the series. For series ≥ 8,gxSetupTurnipDriver()returns early — it doesn't stage the driver or set theGENERALSX_ADRENOTOOLS_*env vars, sovulkan_loader.cppfalls through to the stocklibvulkan.so(its existing, already-implemented path).GENERALSX_NO_TURNIP=1forces the same behaviour on any device — useful for debugging, or for a future a8xx part whosegpu_modelstring this parser doesn't recognise.No change for Adreno 6xx/7xx: they still get Turnip exactly as before.
Testing
Galaxy S26+ (Adreno 840, Android 16, 4 KB-page kernel). With this patch + a companion DXVK presenter fix (
VK_SUBOPTIMAL_KHRhandling — separate PR to the dxvk fork), the port boots to the main menu and plays a skirmish at ~30 FPS. Without it, it crashes atenumAdaptersevery launch.Related: #23