:orphan:

.. title:: CONFIG_DWMAC_NB_TX_DESCS

.. kconfig:: CONFIG_DWMAC_NB_TX_DESCS

CONFIG_DWMAC_NB_TX_DESCS
########################

*Number of entries in the transmit descriptor ring*

Type: ``int``

Help
====

.. code-block:: none

    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
===================

\ :kconfig:`ETH_DWMAC <CONFIG_ETH_DWMAC>` && \ :kconfig:`NET_L2_ETHERNET <CONFIG_NET_L2_ETHERNET>`

*(Includes any dependencies from ifs and menus.)*

Default
=======

- 16

Kconfig definition
==================



At ``<Driver>/ethernet/Kconfig.dwmac:42``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:42`` → ``<Driver>/Kconfig:20`` → ``<Driver>/ethernet/Kconfig:53``

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

.. code-block:: kconfig

    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.)*