diff --git a/ggml/src/ggml-webgpu/ggml-webgpu-shader-lib.hpp b/ggml/src/ggml-webgpu/ggml-webgpu-shader-lib.hpp
index 35a55ecaf..0604e1c2b 100644
--- a/ggml/src/ggml-webgpu/ggml-webgpu-shader-lib.hpp
+++ b/ggml/src/ggml-webgpu/ggml-webgpu-shader-lib.hpp
@@ -2815,11 +2815,25 @@ class ggml_webgpu_shader_lib {
         key.common.v_direct &= decisions.use_sg_matrix && key.common.v_type == GGML_TYPE_F16;
         key.use_sg_matrix = decisions.use_sg_matrix;
 
-        const uint32_t max_kv_tile = ggml_webgpu_flash_attn_max_kv_tile(
+        uint32_t max_kv_tile = ggml_webgpu_flash_attn_max_kv_tile(
             context.wg_mem_limit_bytes, decisions.q_tile, decisions.use_sg_matrix ? context.sg_mat_n : 1u,
             key.common.head_dim_qk, key.common.head_dim_v, key.common.has_mask,
             key.common.k_direct || key.common.v_direct);
-        GGML_ASSERT(max_kv_tile > 0);
+
+        // WorkGroup storage size isn't enough for some params with subgroup matrices path (ref. https://github.com/ggml-org/llama.cpp/pull/26566)
+        if (max_kv_tile == 0) {
+            GGML_ASSERT(decisions.use_sg_matrix);
+            // switch to flash_attn_reg_tile path
+            decisions.use_sg_matrix = false;
+            decisions.q_tile        = GGML_WEBGPU_FLASH_ATTN_TILE_Q_TILE;
+            key.common.k_direct     = false;
+            key.common.v_direct     = false;
+            key.use_sg_matrix       = false;
+            max_kv_tile             = ggml_webgpu_flash_attn_max_kv_tile(
+                context.wg_mem_limit_bytes, decisions.q_tile, 1u, key.common.head_dim_qk, key.common.head_dim_v,
+                key.common.has_mask, key.common.k_direct || key.common.v_direct);
+            GGML_ASSERT(max_kv_tile > 0);
+        }
 
         decisions.kv_tile = decisions.use_sg_matrix ?
                                 std::min(max_kv_tile, context.sg_mat_n * GGML_WEBGPU_FLASH_ATTN_PREFERRED_KV_SG_TILES) :
@@ -2993,6 +3007,10 @@ class ggml_webgpu_shader_lib {
                 defines.push_back("SRC_F16");
                 variant += "_f16";
                 break;
+            case GGML_TYPE_I32:
+                defines.push_back("SRC_I32");
+                variant += "_i32";
+                break;
             default:
                 GGML_ABORT("Unsupported src type for cpy shader");
         }
diff --git a/ggml/src/ggml-webgpu/ggml-webgpu.cpp b/ggml/src/ggml-webgpu/ggml-webgpu.cpp
index ba4b91695..98c716247 100644
--- a/ggml/src/ggml-webgpu/ggml-webgpu.cpp
+++ b/ggml/src/ggml-webgpu/ggml-webgpu.cpp
@@ -4283,9 +4283,8 @@ static bool ggml_backend_webgpu_device_supports_op(ggml_backend_dev_t dev, const
             break;
         case GGML_OP_CPY:
         case GGML_OP_CONT:
-            supports_op = ((op->type == GGML_TYPE_F32 || op->type == GGML_TYPE_F16) &&
-                           (src0->type == GGML_TYPE_F32 || src0->type == GGML_TYPE_F16)) ||
-                          (op->type == GGML_TYPE_I32 && src0->type == GGML_TYPE_F32);
+            supports_op = (op->type == GGML_TYPE_F16 || op->type == GGML_TYPE_F32 || op->type == GGML_TYPE_I32) &&
+                          (src0->type == GGML_TYPE_F16 || src0->type == GGML_TYPE_F32 || src0->type == GGML_TYPE_I32);
             break;
         case GGML_OP_SET:
             supports_op = src0->type == src1->type && src0->type == op->type &&
diff --git a/ggml/src/ggml-webgpu/wgsl-shaders/cpy.wgsl b/ggml/src/ggml-webgpu/wgsl-shaders/cpy.wgsl
index 67f1dc092..0d0d81ab6 100644
--- a/ggml/src/ggml-webgpu/wgsl-shaders/cpy.wgsl
+++ b/ggml/src/ggml-webgpu/wgsl-shaders/cpy.wgsl
@@ -4,6 +4,8 @@ enable f16;
 #define SRC_TYPE f32
 #elif defined(SRC_F16)
 #define SRC_TYPE f16
+#elif defined(SRC_I32)
+#define SRC_TYPE i32
 #endif
 
 #ifdef DST_F32