ESP32P4和PHY的RMII接口设计问题

[dino.tang]

RMII数据接口手册要求成组使用，我使用第二组，GPIO40~GPIOA48,RMII_MDC脚复用GPIO49，但是GPIO49为第三组的TX_EN脚，我这时配置后初始化失败，提示：E (409) esp.emac.gpio: emac_esp_iomux_init(86): GPIO 49 is already reserved
E (409) esp.emac.gpio: emac_esp_iomux_init_rmii(212): invalid TX_EN GPIO number
E (419) esp.emac: emac_esp_config_data_interface(608): invalid EMAC RMII data plane GPIO
E (429) esp.emac: esp_eth_mac_new_esp32(693): config emac interface failed
I (439) gpio: GPIO[49]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
I (439) gpio: GPIO[50]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
E (449) esp_eth: esp_eth_driver_install(189): can't set eth->mac or eth->phy to null
E (459) example_eth_init: eth_init_internal(104): Ethernet driver install failed
E (469) example_eth_init: example_eth_init(265): internal Ethernet init failed
ESP_ERROR_CHECK failed: esp_err_t 0xffffffff (ESP_FAIL) at 0x4001028e
file: "./app/Ethernet.c" line 84
func: Ethernet_example
expression: example_eth_init(&eth_handles, &eth_port_cnt)
有没有大佬帮忙解释一下，是不是MDC脚不能用其他RMII数据脚来使用？