volatile uint32_t *tdt_reg_addr; /**< Address of TDT register. */
uint16_t nb_tx_desc; /**< number of TX descriptors. */
uint16_t tx_tail; /**< current value of TDT reg. */
- uint16_t tx_free_thresh;/**< minimum TX before freeing. */
+ /**< Start freeing TX buffers if there are less free descriptors than
+ this value. */
+ uint16_t tx_free_thresh;
/** Number of TX descriptors to use before RS bit is set. */
uint16_t tx_rs_thresh;
/** Number of TX descriptors used since RS bit was set. */