SDK init ethernet phy trouble

biafra — Wed, 06 Apr 2022 09:55:29 GMT

Hi everyone,

I use RT1064 with LAN 8720A phy, MCUXpresso 11.5.0 and SDK 2.11.0.

Below there is the ethernetif_phy_init() function:

void ethernetif_phy_init(struct ethernetif *ethernetif, const ethernetif_config_t *ethernetifConfig, phy_speed_t *speed, phy_duplex_t *duplex) { status_t status; bool link = false; bool autonego = false; uint32_t initWaitCount = 0; uint32_t autoWaitCount = 0; phy_config_t phyConfig = { .phyAddr = ethernetifConfig->phyHandle->phyAddr, .autoNeg = true, }; ethernetifConfig->phyHandle->mdioHandle->resource.base = *ethernetif_enet_ptr(ethernetif); LWIP_PLATFORM_DIAG(("Initializing PHY...")); while ((initWaitCount < ENET_ATONEGOTIATION_TIMEOUT) && (!(link && autonego))) { status = PHY_Init(ethernetifConfig->phyHandle, &phyConfig); if (kStatus_Success != status) { LWIP_ASSERT("\r\nCannot initialize PHY.\r\n", 0); } /* Wait for auto-negotiation success and link up */ autoWaitCount = ENET_ATONEGOTIATION_TIMEOUT; do { PHY_GetAutoNegotiationStatus(ethernetifConfig->phyHandle, &autonego); PHY_GetLinkStatus(ethernetifConfig->phyHandle, &link); if (autonego && link) { break; } } while (--autoWaitCount); if (!autonego) { PRINTF("PHY Auto-negotiation failed. Please check the cable connection and link partner setting.\r\n"); } initWaitCount++; } if (autonego && link) { /* Get the actual PHY link speed. */ PHY_GetLinkSpeedDuplex(ethernetifConfig->phyHandle, speed, duplex); } #if 0 /* Disable assert. If initial auto-negation is timeout, \ \ the ENET is set to default (100Mbs and full-duplex). */ else { LWIP_ASSERT("\r\nGiving up PHY initialization. Please check the ENET cable connection and link partner setting and reset the board.\r\n", 0); } #endif }

I think there is a potential problem.

After the PHY_Init() function the phy is checked for the autonego completion with PHY_GetAutoNegotiationStatus() and PHY_GetLinkStatus() functions. In my case the exit from the inner do-while loop occurs after 6000 to 8000 cycles, so I assigned:

#define ENET_ATONEGOTIATION_TIMEOUT (0x3FFFU)

in the lwiopts.h file. This way when the cable is plugged the main while loop is executed only once and the ethernetif_phy_init() function exits immediately.

But if the cable is not plugged, the main while loop is executed ENET_ATONEGOTIATION_TIMEOUT times, and every time the inner do-while loop is executed ENET_ATONEGOTIATION_TIMEOUT times: in this case the the ethernetif_phy_init() function exits in several hours.

This happens because ENET_ATONEGOTIATION_TIMEOUT is used for both the main while loop and the inner do-while loop and it should be high enough to wait for the autonego completion with the cable plugged, but low enough not to wait too long with the cable unplugged.

I suggest the use of different #define constants for every loop as in older SDK version (up to 2.82 there was ENET_ATONEGOTIATION_TIMEOUT and PHY_TIMEOUT_COUNT constants).

Many thanks

Biafra

Re: SDK init ethernet phy trouble

diego_charles — Thu, 14 Apr 2022 04:50:53 GMT

Hi @biafra

Many thanks for your the valuable report/suggestion, I will deliver it to the respective team.

All the best,

Diego.

topic SDK init ethernet phy trouble in MCUXpresso IDE

SDK init ethernet phy trouble

Re: SDK init ethernet phy trouble