Merge "Bluetooth HAL: Add missing retry logic to the H4Protocol::Send()" into main am: 1be3989c

}

size_t H4Protocol::Send(PacketType type, const uint8_t* data, size_t length) {

  /* For HCI communication over USB dongle, multiple write results in

   * response timeout as driver expect type + data at once to process

   * the command, so using "writev"(for atomicity) here.

   */

  struct iovec iov[2];

  ssize_t ret = 0;

  iov[0].iov_base = &type;

  iov[0].iov_len = sizeof(type);

  iov[1].iov_base = (void*)data;

  iov[1].iov_len = length;

  while (1) {

    ret = TEMP_FAILURE_RETRY(writev(uart_fd_, iov, 2));

  struct iovec iov_array[] = {{&type, sizeof(type)},

                              {const_cast<uint8_t*>(data), length}};

  size_t iovcnt = sizeof(iov_array) / sizeof(iov_array[0]);

  struct iovec* iov = iov_array;

  size_t total_bytes = sizeof(type) + length;

  size_t remaining_bytes = total_bytes;

  size_t bytes_written = 0;

  while (remaining_bytes > 0) {

    ssize_t ret = TEMP_FAILURE_RETRY(writev(uart_fd_, iov, iovcnt));

    if (ret == -1) {

      LOG_ALWAYS_FATAL("%s error writing to UART (%s)", __func__,

                       strerror(errno));

      if (errno == EAGAIN) continue;

      ALOGE("Error writing to UART (%s)", strerror(errno));

      break;

    } else if (ret == 0) {

      // Nothing written :(

      ALOGE("%s zero bytes written - something went wrong...", __func__);

      break;

    }

    } else if (ret == remaining_bytes) {

      // Everything written

      bytes_written += ret;

      break;

    }

  return ret;

    // Updating counters for partial writes

    bytes_written += ret;

    remaining_bytes -= ret;

    ALOGW("%s: %zu/%zu bytes written - retrying remaining %zu bytes", __func__,

          bytes_written, total_bytes, remaining_bytes);

    // Remove fully written iovs from the list

    while (ret >= iov->iov_len) {

      ret -= iov->iov_len;

      ++iov;

      --iovcnt;

    }

    // Adjust the iov to point to the remaining data that needs to be written

    if (ret > 0) {

      iov->iov_base = static_cast<uint8_t*>(iov->iov_base) + ret;

      iov->iov_len -= ret;

    }

  }

  return total_bytes - remaining_bytes;

}

size_t H4Protocol::OnPacketReady(const std::vector<uint8_t>& packet) {