STM32MP135 - ETH SWRESET fails, ETH_DMAMR_SWR stays set and then timeout

[SteMMo]

Hello everyone,

i'm working on a custom SOC based on ST32MP135 and LAN8710 ethernet phy chip.

When the HAL_ETH_Init() code runs and sends the module reset by setting the ETH_DMAMR_SWR bit, the loop exits with the HAL_ETH_ERROR_TIMEOUT.

The current interface is set to SYSCFG_ETH1_RMII value and the clock source is set by the following code:

HAL_RCCEx_PeriphCLKConfig(&(RCC_PeriphCLKInitTypeDef){
	.PeriphClockSelection = RCC_PERIPHCLK_ETH1,
	.Eth1ClockSelection = RCC_ETH1CLKSOURCE_PLL4
});

  The HAL_ETH_MspInit() function sets the GPIOs and enables the clocks:

		/* Enable GPIOs clocks */
		__HAL_RCC_GPIOA_CLK_ENABLE();
		__HAL_RCC_GPIOB_CLK_ENABLE();
		__HAL_RCC_GPIOC_CLK_ENABLE();
		__HAL_RCC_GPIOG_CLK_ENABLE();

		/* Ethernet MSP init:
		REF_CLK  -------------> PA11
		TXD0    --------------> PG13
		TXD1    --------------> PG14
		RXD0    --------------> PC4
		RXD1    --------------> PC5
		TX_EN   --------------> PB11
		CRS_DV  --------------> PC1
		MDC     --------------> PG2
		MDIO    --------------> PA2
		*/

		/* Configure PA11 = ETH1_CLK */
		GPIO_InitStructure.Pin =  GPIO_PIN_11;
		GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_MEDIUM;
		GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
		GPIO_InitStructure.Pull = GPIO_NOPULL;
		GPIO_InitStructure.Alternate = GPIO_AF11_ETH;
		HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

		/* Configure PA2 = ETH1_MDIO */
		GPIO_InitStructure.Pin =  GPIO_PIN_2;
		GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
		GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
		GPIO_InitStructure.Pull = GPIO_NOPULL;
		GPIO_InitStructure.Alternate = GPIO_AF11_ETH;
		HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

		/* Configure PB11 = ETH1_TX_EN */
		GPIO_InitStructure.Pin = GPIO_PIN_11;
		GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_MEDIUM;
		HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);

		/* Configure PC1 = ETH1_CRS_DV */
		GPIO_InitStructure.Pin = GPIO_PIN_1;
		GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
		GPIO_InitStructure.Pull = GPIO_NOPULL;
		GPIO_InitStructure.Alternate = GPIO_AF10_ETH;
		HAL_GPIO_Init(GPIOC, &GPIO_InitStructure);

		/* Configure PC4 = ETH1_RXD0 and PC5 = ETH1_RXD1 */
		GPIO_InitStructure.Pin = GPIO_PIN_4 | GPIO_PIN_5;
		GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
		GPIO_InitStructure.Pull = GPIO_NOPULL;
		GPIO_InitStructure.Alternate = GPIO_AF11_ETH;
		HAL_GPIO_Init(GPIOC, &GPIO_InitStructure);

		/* Configure PG2 = ETH1_MDC, PG13 = ETH1_TXD0 and PG14 = ETH1_TXD1 */
		GPIO_InitStructure.Pin = GPIO_PIN_2 | GPIO_PIN_13 | GPIO_PIN_14;
		GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
		GPIO_InitStructure.Pull = GPIO_NOPULL;
		GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_MEDIUM;
		GPIO_InitStructure.Alternate = GPIO_AF11_ETH;
		HAL_GPIO_Init(GPIOG, &GPIO_InitStructure);

		/* Enable Ethernet clocks */
		__HAL_RCC_ETH1CK_CLK_ENABLE();
		__HAL_RCC_ETH1MAC_CLK_ENABLE();
		__HAL_RCC_ETH1TX_CLK_ENABLE();
		__HAL_RCC_ETH1RX_CLK_ENABLE();

		/* Configure IRQ */
		IRQ_SetPriority(ETH1_IRQn, 7);
		IRQ_Enable(ETH1_IRQn);

 Touching the pin 5 (CLKIN) of the PHY I see a 50MHz clock.

Any idea about the timeout?

Regards

[SteMMo]

Found the solution here: 

https://community.st.com/t5/stm32-mpus-products-and-hardware/stm32mp135-baremetal-ethernet2/m-p/636786/highlight/true#M10829 

[PatrickF]

Hi @SteMMo 

this kind of error usually come from lack of clock going to ETH IP (eth_mii_tx_clk and eth_mii_rx_clk).
Apart settings in RCC, please have a look to this figure from RM0475 and set SYSCFG according to your HW board setup to ensure correct clock paths are selected.
AN5474 could also help.

Regards.