diff options
Diffstat (limited to 'host/lib/usrp')
| -rw-r--r-- | host/lib/usrp/b200/b200_impl.cpp | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/host/lib/usrp/b200/b200_impl.cpp b/host/lib/usrp/b200/b200_impl.cpp index a034ef632..239bd97b1 100644 --- a/host/lib/usrp/b200/b200_impl.cpp +++ b/host/lib/usrp/b200/b200_impl.cpp @@ -536,18 +536,27 @@ b200_impl::b200_impl(const uhd::device_addr_t& device_addr, usb_device_handle::s << " is too large. It will be set to " << B200_USB_DATA_MAX_RECV_FRAME_SIZE << "."; recv_frame_size = B200_USB_DATA_MAX_RECV_FRAME_SIZE; - } else if (recv_frame_size % max_transfer == 0) { + } else if (recv_frame_size % max_transfer == 0 or recv_frame_size % 8 != 0) { // The Cypress FX3 does not properly handle recv_frame_sizes that are - // aligned to the maximum transfer size. The code below coerces the - // recv_frame_size down to a value that is not a multiple of of the - // maximum transfer size and aligns to full 8 byte words for sc8, sc12, - // and sc16 data types for best performance on the FPGA. - recv_frame_size = (((recv_frame_size - 16) / 24) * 24) + 16; + // aligned to the maximum transfer size and the FPGA code requires the + // data to be aligned to 8 byte words. The code below coerces the + // recv_frame_size to a value that is a multiple of 8 bytes, not + // a multiple of the maximum transfer size, and aligned to 24 bytes + // to support full 8 byte word alignment for sc8, sc12, and sc16 data + // types. + + // Align to 8 byte words + recv_frame_size += 8 - (recv_frame_size % 8); + if (recv_frame_size % max_transfer == 0) { + recv_frame_size = (((recv_frame_size - 16) / 24) * 24) + 16; + } UHD_LOGGER_WARNING("B200") - << "Multiples of 512 not supported for recv_frame_size. " - << "Requested recv_frame_size of " << device_addr["recv_frame_size"] - << " reduced to " << recv_frame_size << "."; + << "The recv_frame_size must be a multiple of 8 bytes and not a multiple of " + << max_transfer << " bytes. Requested recv_frame_size of " + << device_addr["recv_frame_size"] + << " coerced to " << recv_frame_size << "."; } + data_xport_args["recv_frame_size"] = std::to_string(recv_frame_size); data_xport_args["num_recv_frames"] = device_addr.get("num_recv_frames", "16"); data_xport_args["send_frame_size"] = device_addr.get("send_frame_size", std::to_string(B200_USB_DATA_DEFAULT_FRAME_SIZE)); |