From abee6b1929390e4824964f9fc2b3ed538dc3c679 Mon Sep 17 00:00:00 2001 From: Martin Braun Date: Tue, 25 Oct 2016 15:09:06 -0700 Subject: x300: Throttle MTU to 3000 for PCIe to avoid underruns This is a temporary workaround to make PCIe available on lower rates. --- host/lib/usrp/x300/x300_impl.hpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'host/lib') diff --git a/host/lib/usrp/x300/x300_impl.hpp b/host/lib/usrp/x300/x300_impl.hpp index ee42dcf3e..5d3fa4fed 100644 --- a/host/lib/usrp/x300/x300_impl.hpp +++ b/host/lib/usrp/x300/x300_impl.hpp @@ -54,7 +54,10 @@ static const size_t X300_RX_SW_BUFF_SIZE_ETH_MACOS = 0x100000; //1Mib //where an element is 8 bytes. For best throughput ensure that the data frame fits in these buffers. //Also ensure that the kernel has enough frames to hold buffered TX and RX data static const size_t X300_PCIE_RX_DATA_FRAME_SIZE = 8184; //bytes -static const size_t X300_PCIE_TX_DATA_FRAME_SIZE = 8192; //bytes +//static const size_t X300_PCIE_TX_DATA_FRAME_SIZE = 8192; //bytes +// This is a temporary solution: We're throttling PCIe MTU to avoid +// underruns on Tx. Once we solve it on the FPGA side, need revert this commit. +static const size_t X300_PCIE_TX_DATA_FRAME_SIZE = 3000; //bytes static const size_t X300_PCIE_DATA_NUM_FRAMES = 2048; static const size_t X300_PCIE_MSG_FRAME_SIZE = 256; //bytes static const size_t X300_PCIE_MSG_NUM_FRAMES = 64; -- cgit v1.2.3