CONFIG_DWMAC_NB_RX_DESCS

Number of entries in the receive descriptor ring

Type: int

Help

Received packets are spread across the required number of fragment
buffers. Each RX fragment has a size of CONFIG_NET_BUF_DATA_SIZE.
There is one descriptor entry per fragment.

A higher number allows for more packets to be received without
immediate intervention from the CPU but requires more transient
memory. A smaller number increases the risk of an overflow and
dropped packets.

Direct dependencies

ETH_DWMAC && NET_L2_ETHERNET

(Includes any dependencies from ifs and menus.)

Default

16

Kconfig definition

At <Zephyr>/drivers/ethernet/Kconfig.dwmac:55

Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:42 → <Zephyr>/drivers/Kconfig:20 → <Zephyr>/drivers/ethernet/Kconfig:53

Menu path: (Top) → Device Drivers → Ethernet Drivers → Synopsys DesignWare MAC driver

config DWMAC_NB_RX_DESCS
    int "Number of entries in the receive descriptor ring"
    range 4 128
    default 16
    depends on ETH_DWMAC && NET_L2_ETHERNET
    help
      Received packets are spread across the required number of fragment
      buffers. Each RX fragment has a size of CONFIG_NET_BUF_DATA_SIZE.
      There is one descriptor entry per fragment.

      A higher number allows for more packets to be received without
      immediate intervention from the CPU but requires more transient
      memory. A smaller number increases the risk of an overflow and
      dropped packets.

(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)