[ETH] two constants specifying the size of the Rx Buff

[DedkovArtem]

I use STM32F429IITx + FreeRTOS + ETH+ LWIP. In my opinion, two constants set the same thing.

First constant In the file lwipopts.h #define ETH_RX_BUFFER_SIZE 1536 Its value can be configured via Cube using the Rx Buffers Length input field.

Second constant In the file stm32f4xx_hal_conf.h #define ETH_RX_BUF_SIZE ETH_MAX_PACKET_SIZE which refers to the file stm32f4xx_hal_eth.h in which the constant is declared #define ETH_MAX_PACKET_SIZE ((uint32_t)1528U) its value cannot be changed via Cube

A) ETH_RX_BUFFER_SIZE is used when describing the type RxBuff_t ETH_RX_BUF_SIZE is used when configuring the DMARxDscrTab in the static void procedure ETH_DMARxDescListInit(ETH_HandleTypeDef *heth) dmarxdesc->DESC1 = ETH_DMARXDESC_RCH | ETH_RX_BUF_SIZE; Both constants define the size of the same array. ETH_RX_BUFFER_SIZE allocates space in RAM for it, and ETH_RX_BUF_SIZE configure Eth controller the available buffer size.

B) The ETH_RX_BUFFER_SIZE value (not a reference) is used in the static void low_level_init(struct netif *netif) function heth.Init.RxBuffLen = 1536; it would be logical to change to heth.Init.RxBuffLen = ETH_RX_BUFFER_SIZE ;

[ASELSTM]

ST Internal Reference: 128005

[ASELSTM]

Hi @DedkovArtem,

Thank you for your contribution. This issue has been fixed in the frame of version v1.27.1 of the STM32CubeF4. Please allow me then to close this thread.

With regards,