435 /**

   436    Gibt die Zählerstände der CRC-Fault-Counter aus und setzt diese zurück.

   437 

   438    \return 0 bei Erfolg, sonst < 0

   439 */

   440 

   441 int ec_slave_check_crc(ec_slave_t *slave /**< EtherCAT-Slave */)

   442 {

   443     ec_frame_t frame;

   444     uint8_t data[4];

   445     uint16_t crc[2];

   446 

   447     ec_frame_init_nprd(&frame, slave->master, slave->station_address, 0x0300,

   448                        4);

   449 

   450     if (unlikely(ec_frame_send_receive(&frame))) {

   451         printk(KERN_WARNING "EtherCAT: Reading CRC fault counters failed"

   452                " on slave %i - Could not send command!\n",

   453                slave->ring_position);

   454         return -1;

   455     }

   456 

   457     if (unlikely(frame.working_counter != 1)) {

   458         printk(KERN_WARNING "EtherCAT: Reading CRC fault counters -"

   459                " Slave %i did not respond!\n", slave->ring_position);

   460         return -1;

   461     }

   462 

   463     crc[0] = frame.data[0] | (frame.data[1] << 8);

   464     crc[1] = frame.data[2] | (frame.data[3] << 8);

   465 

   466     // No CRC faults.

   467     if (!crc[0] && !crc[1]) return 0;

   468 

   469     printk(KERN_INFO "EtherCAT: CRC faults on slave %i. A: %i, B: %i\n",

   470            slave->ring_position, crc[0], crc[1]);

   471 

   472     // Reset CRC counters

   473     memset(data, 0x00, 4);

   474     ec_frame_init_npwr(&frame, slave->master, slave->station_address, 0x0300,

   475                        4, data);

   476 

   477     if (unlikely(ec_frame_send_receive(&frame))) return -1;

   478 

   479     if (unlikely(frame.working_counter != 1)) {

   480         printk(KERN_ERR "EtherCAT: Resetting CRC fault counters - Slave"

   481                " %i did not respond!\n", slave->ring_position);

   482         return -1;

   483     }

   484 

   485     return 0;

   486 }

   487 

   488 /*****************************************************************************/

   489