CONFIG_DWMAC_NB_TX_DESCS

Number of entries in the transmit descriptor ring

Type: int

Help

A higher number allows for more packets to be queued which may
improve throughput, but that requires more transient memory.
However there must be enough descriptors to hold all fragments
of a full-size packet to be transmitted or the packet will be
dropped.

Fragment size is influenced by CONFIG_NET_BUF_DATA_SIZE.

Direct dependencies

ETH_DWMAC && NET_L2_ETHERNET

(Includes any dependencies from ifs and menus.)

Default

16

Kconfig definition

At <Zephyr>/drivers/ethernet/Kconfig.dwmac:42

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_TX_DESCS
    int "Number of entries in the transmit descriptor ring"
    range 4 128
    default 16
    depends on ETH_DWMAC && NET_L2_ETHERNET
    help
      A higher number allows for more packets to be queued which may
      improve throughput, but that requires more transient memory.
      However there must be enough descriptors to hold all fragments
      of a full-size packet to be transmitted or the packet will be
      dropped.

      Fragment size is influenced by CONFIG_NET_BUF_DATA_SIZE.

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