gr-fosphor: error: work group size exceeds the maximum default value for the selected device (AMD HD 5450)

Dear list, I just compiled gr-fosphor on a PC equipped with a HD 5450 card, and when I try to run osmocom_fft -F I gut the following error: root@TH-SDR1:~/gr-fosphor/gr-fosphor/lib/fosphor# osmocom_fft -F linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.008.001-42-g8c87a524 gr-osmosdr v0.1.4-8-g46bb1ad1 (0.1.5git) gnuradio 3.7.5.1 built-in source types: file fcd rtl rtl_tcp uhd hackrf bladerf rfspace -- Operating over USB 3. -- Initialize CODEC control... -- Initialize Radio control... -- Performing register loopback test... pass -- Performing CODEC loopback test... pass -- Asking for clock rate 32.000000 MHz... -- Actually got clock rate 32.000000 MHz. -- Performing timer loopback test... pass -- Setting master clock rate selection to 'automatic'. -- Using subdev spec 'A:A'. [+] Selected device: Cedar Build log for 'display.cl': "/tmp/OCL2287T8.cl", line 67: error: work group size exceeds the maximum default value for the selected device __attribute__((reqd_work_group_size(16, 16, 1))) ^ 1 error detected in the compilation of "/tmp/OCL2287T8.cl". Frontend phase failed compilation. --- [!] CL Error (-11, /root/gr-fosphor/gr-fosphor/lib/fosphor/cl.c:344): Failed to build program I installed the latest stable driver and APP-SDK. oot@TH-SDR1:~/gr-fosphor/gr-fosphor/lib/fosphor# fglrxinfo display: :0.0 screen: 0 OpenGL vendor string: Advanced Micro Devices, Inc. OpenGL renderer string: AMD Radeon HD 5450 OpenGL version string: 4.4.13283 Compatibility Profile Context 14.501.1003 Here is the info about the card: NAME: Cedar VENDOR: Advanced Micro Devices, Inc. PROFILE: FULL_PROFILE VERSION: OpenCL 1.2 AMD-APP (1642.5) EXTENSIONS: cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_atomic_counters_32 cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_media_ops2 cl_amd_popcnt cl_amd_image2d_from_buffer_read_only cl_khr_spir cl_khr_gl_event DRIVER_VERSION: 1642.5 Type: GPU EXECUTION_CAPABILITIES: Kernel GLOBAL_MEM_CACHE_TYPE: None (0) CL_DEVICE_LOCAL_MEM_TYPE: Local (1) SINGLE_FP_CONFIG: 0x3e QUEUE_PROPERTIES: 0x2 VENDOR_ID: 4098 MAX_COMPUTE_UNITS: 2 MAX_WORK_ITEM_DIMENSIONS: 3 MAX_WORK_GROUP_SIZE: 128 PREFERRED_VECTOR_WIDTH_CHAR: 16 PREFERRED_VECTOR_WIDTH_SHORT: 8 PREFERRED_VECTOR_WIDTH_INT: 4 PREFERRED_VECTOR_WIDTH_LONG: 2 PREFERRED_VECTOR_WIDTH_FLOAT: 4 PREFERRED_VECTOR_WIDTH_DOUBLE: 0 MAX_CLOCK_FREQUENCY: 650 ADDRESS_BITS: 32 MAX_MEM_ALLOC_SIZE: 134217728 IMAGE_SUPPORT: 1 MAX_READ_IMAGE_ARGS: 128 MAX_WRITE_IMAGE_ARGS: 8 IMAGE2D_MAX_WIDTH: 16384 IMAGE2D_MAX_HEIGHT: 16384 IMAGE3D_MAX_WIDTH: 2048 IMAGE3D_MAX_HEIGHT: 2048 IMAGE3D_MAX_DEPTH: 2048 MAX_SAMPLERS: 16 MAX_PARAMETER_SIZE: 1024 MEM_BASE_ADDR_ALIGN: 2048 MIN_DATA_TYPE_ALIGN_SIZE: 128 GLOBAL_MEM_CACHELINE_SIZE: 0 GLOBAL_MEM_CACHE_SIZE: 0 GLOBAL_MEM_SIZE: 268435456 MAX_CONSTANT_BUFFER_SIZE: 65536 MAX_CONSTANT_ARGS: 8 LOCAL_MEM_SIZE: 32768 ERROR_CORRECTION_SUPPORT: 0 PROFILING_TIMER_RESOLUTION: 1 ENDIAN_LITTLE: 1 AVAILABLE: 1 COMPILER_AVAILABLE: 1 MAX_WORK_GROUP_SIZES: 128 128 128 --------------------------------------------------------------------- If someone can suggest what else to try, it will be appreciated. Thanks, Csaba