From d2c9fdddcb9ed2884fc75e1be7d505088cd93a83 Mon Sep 17 00:00:00 2001
From: Concedo <39025047+LostRuins@users.noreply.github.com>
Date: Mon, 25 Aug 2025 11:06:48 +0800
Subject: [PATCH] old gpu fattn fix

---
 ggml/src/ggml-cuda/fattn.cu | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ggml/src/ggml-cuda/fattn.cu b/ggml/src/ggml-cuda/fattn.cu
index 3440ed287..f8b492f8c 100644
--- a/ggml/src/ggml-cuda/fattn.cu
+++ b/ggml/src/ggml-cuda/fattn.cu
@@ -415,6 +415,11 @@ static best_fattn_kernel ggml_cuda_get_best_fattn_kernel(const int device, const
         return BEST_FATTN_KERNEL_WMMA_F16;
     }
 
+    //kcpp: always force WMMA for older gpus, fix issues like "FlashAttention without tensor cores only supports head sizes 64 and 128."
+    if (ggml_cuda_highest_compiled_arch(cc) <= GGML_CUDA_CC_TURING || cc == GGML_CUDA_CC_TURING) {
+        return BEST_FATTN_KERNEL_WMMA_F16;
+    }
+
     // If there is no suitable kernel for tensor cores or small batch sizes, use the generic kernel for large batch sizes:
     if (prec == GGML_PREC_DEFAULT && fast_fp16_available(cc)) {
         return BEST_FATTN_KERNEL_TILE_F16;