Electrical – stm32f10x cmsis spi driver

I'm trying to connect raspberry pi with stm32f103 over SPI where stm is a slave.

I'm not really like SPL and also I found awesome cmsis drivers
for peripheral from Keil so I decided to use them.

Well, the problem is that I can't send any data to RPi. Reading works nice: everything I send from RPi is caught by STM but nothing is on the MISO line.

Here is my SPI initialization and some used definitions:

#define FRAME_START_POS             0
#define FRAME_TYPE_POS              1
#define FRAME_DATA_POS              2

#define FRAME_START_BYTE            0x1B
#define FRAME_TYPE_START            0x01
#define FRAME_TYPE_DATA             0x02

#define FRAME_HEADER_SIZE           2

#define RPI_SPI                     Driver_SPI2


void SpiInit(void)
{
    out_data[FRAME_START_POS] = FRAME_START_BYTE;
    out_data[FRAME_TYPE_POS] = FRAME_TYPE_DATA;

    if(RPI_SPI.Initialize(RpiSpiCb) != 0)
    {
        LOGGING_Error("Can not initialize SPI");
    }

    if(RPI_SPI.PowerControl(ARM_POWER_FULL) != 0)
    {
        LOGGING_Error("Can't set SPI power");
    }

    int status = RPI_SPI.Control(ARM_SPI_MODE_SLAVE    |
                                 ARM_SPI_SS_SLAVE_HW   |
                                 ARM_SPI_CPOL0_CPHA0   |
                                 ARM_SPI_DATA_BITS(8U) |
                                 ARM_SPI_MSB_LSB,       RPI_SPI_BUS_SPEED);

    if(status == -1)
    {
        System_ErrorLedOn();
        LOGGING_Error("Can't set SPI control");
    }
}


static void transfer_headers(void)
{
    /* 
     * out_data[0] and out_data[1] are never seen 
     *  on the MISO line but in_data is filled.
     */
    if(RPI_SPI.Transfer((void*)out_data, (void*)in_data, FRAME_HEADER_SIZE) != 0)
    {
        LOGGING_Error("Can't transfer data over SPI");
    }

    state = READ_HEADER;
}

I can't find out what I'm missing here. Maybe sending data when you are a slave is tricky but I haven't found anything about that?

P.S. Using RPI_SPI.Send() instead of Transfer() also does not work.

UPDATE

Here is function that is used to send data from RPi:

def __send_data(self, data):
    ans = self.stm.xfer2(data)

    if ((ans[FRAME_START_POS] != FRAME_START_BYTE) or
       (ans[FRAME_TYPE_POS] != FRAME_TYPE_DATA)):

        raise IOError("Wrong bytes in header from stm: 0x%02x 0x%02x" %
                      (ans[FRAME_START_POS], ans[FRAME_TYPE_POS]))

    if len(ans) > FRAME_HEADER_SIZE:
        return ans[FRAME_HEADER_SIZE:]

    return []