esp_eth: EMAC start/stop optimization

components/esp_eth/src/esp_eth.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2019-2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2019-2022 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -265,7 +265,6 @@ esp_err_t esp_eth_start(esp_eth_handle_t hdl)
     esp_eth_driver_t *eth_driver = (esp_eth_driver_t *)hdl;
     ESP_GOTO_ON_FALSE(eth_driver, ESP_ERR_INVALID_ARG, err, TAG, "ethernet driver handle can't be null");
     esp_eth_phy_t *phy = eth_driver->phy;
-    esp_eth_mac_t *mac = eth_driver->mac;
     // check if driver has stopped
     esp_eth_fsm_t expected_fsm = ESP_ETH_FSM_STOP;
     ESP_GOTO_ON_FALSE(atomic_compare_exchange_strong(&eth_driver->fsm, &expected_fsm, ESP_ETH_FSM_START),
@@ -274,7 +273,6 @@ esp_err_t esp_eth_start(esp_eth_handle_t hdl)
     if (eth_driver->auto_nego_en == true) {
         ESP_GOTO_ON_ERROR(phy->autonego_ctrl(phy, ESP_ETH_PHY_AUTONEGO_RESTART, &eth_driver->auto_nego_en), err, TAG, "phy negotiation failed");
     }
-    ESP_GOTO_ON_ERROR(mac->start(mac), err, TAG, "start mac failed");
     ESP_GOTO_ON_ERROR(esp_event_post(ETH_EVENT, ETHERNET_EVENT_START, &eth_driver, sizeof(esp_eth_driver_t *), 0),
                       err, TAG, "send ETHERNET_EVENT_START event failed");
     ESP_GOTO_ON_ERROR(phy->get_link(phy), err, TAG, "phy get link status failed");

components/esp_eth/src/esp_eth_mac_esp.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2019-2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2019-2022 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -33,7 +33,7 @@
 static const char *TAG = "esp.emac";
 
 #define PHY_OPERATION_TIMEOUT_US (1000)
-#define MAC_STOP_TIMEOUT_MS (100)
+#define MAC_STOP_TIMEOUT_US (250)
 #define FLOW_CONTROL_LOW_WATER_MARK (CONFIG_ETH_DMA_RX_BUFFER_NUM / 3)
 #define FLOW_CONTROL_HIGH_WATER_MARK (FLOW_CONTROL_LOW_WATER_MARK * 2)
 
@@ -65,6 +65,8 @@ typedef struct {
 
 static esp_err_t esp_emac_alloc_driver_obj(const eth_mac_config_t *config, emac_esp32_t **emac_out_hdl, void **out_descriptors);
 static void esp_emac_free_driver_obj(emac_esp32_t *emac, void *descriptors);
+static esp_err_t emac_esp32_start(esp_eth_mac_t *mac);
+static esp_err_t emac_esp32_stop(esp_eth_mac_t *mac);
 
 static esp_err_t emac_esp32_set_mediator(esp_eth_mac_t *mac, esp_eth_mediator_t *eth)
 {
@@ -151,11 +153,11 @@ static esp_err_t emac_esp32_set_link(esp_eth_mac_t *mac, eth_link_t link)
     switch (link) {
     case ETH_LINK_UP:
         ESP_GOTO_ON_ERROR(esp_intr_enable(emac->intr_hdl), err, TAG, "enable interrupt failed");
-        emac_hal_start(&emac->hal);
+        emac_esp32_start(mac);
         break;
     case ETH_LINK_DOWN:
         ESP_GOTO_ON_ERROR(esp_intr_disable(emac->intr_hdl), err, TAG, "disable interrupt failed");
-        emac_hal_stop(&emac->hal);
+        emac_esp32_stop(mac);
         break;
     default:
         ESP_GOTO_ON_FALSE(false, ESP_ERR_INVALID_ARG, err, TAG, "unknown link status");
@@ -387,9 +389,9 @@ static esp_err_t emac_esp32_stop(esp_eth_mac_t *mac)
         if ((ret = emac_hal_stop(&emac->hal)) == ESP_OK) {
             break;
         }
-        to += 20;
-        vTaskDelay(pdMS_TO_TICKS(20));
-    } while (to < MAC_STOP_TIMEOUT_MS);
+        to += 25;
+        esp_rom_delay_us(25);
+    } while (to < MAC_STOP_TIMEOUT_US);
     return ret;
 }
 

components/hal/emac_hal.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -337,18 +337,17 @@ void emac_hal_start(emac_hal_context_t *hal)
 
     /* Flush Transmit FIFO */
     emac_ll_flush_trans_fifo_enable(hal->dma_regs, true);
-    /* Flush Receive FIFO */
-    emac_ll_flush_recv_frame_enable(hal->dma_regs, true);
 
-    /* Enable transmit state machine of the MAC for transmission on the MII */
-    emac_ll_transmit_enable(hal->mac_regs, true);
-    /* Enable receive state machine of the MAC for reception from the MII */
-    emac_ll_receive_enable(hal->mac_regs, true);
     /* Start DMA transmission */
     emac_ll_start_stop_dma_transmit(hal->dma_regs, true);
     /* Start DMA reception */
     emac_ll_start_stop_dma_receive(hal->dma_regs, true);
 
+    /* Enable transmit state machine of the MAC for transmission on the MII */
+    emac_ll_transmit_enable(hal->mac_regs, true);
+    /* Enable receive state machine of the MAC for reception from the MII */
+    emac_ll_receive_enable(hal->mac_regs, true);
+
     /* Clear all pending interrupts */
     emac_ll_clear_all_pending_intr(hal->dma_regs);
 }
@@ -357,18 +356,24 @@ esp_err_t emac_hal_stop(emac_hal_context_t *hal)
 {
     /* Stop DMA transmission */
     emac_ll_start_stop_dma_transmit(hal->dma_regs, false);
-    /* Stop DMA reception */
-    emac_ll_start_stop_dma_receive(hal->dma_regs, false);
 
     if (emac_ll_transmit_frame_ctrl_status(hal->mac_regs) != 0x0) {
         /* Previous transmit in progress */
         return ESP_ERR_INVALID_STATE;
     }
 
-    /* Disable receive state machine of the MAC for reception from the MII */
-    emac_ll_transmit_enable(hal->mac_regs, false);
     /* Disable transmit state machine of the MAC for transmission on the MII */
     emac_ll_receive_enable(hal->mac_regs, false);
+    /* Disable receive state machine of the MAC for reception from the MII */
+    emac_ll_transmit_enable(hal->mac_regs, false);
+
+    if (emac_ll_receive_read_ctrl_state(hal->mac_regs) != 0x0) {
+        /* Previous receive copy in progress */
+        return ESP_ERR_INVALID_STATE;
+    }
+
+    /* Stop DMA reception */
+    emac_ll_start_stop_dma_receive(hal->dma_regs, false);
 
     /* Disable Ethernet MAC and DMA Interrupt */
     emac_ll_disable_all_intr(hal->dma_regs);

components/hal/esp32/include/hal/emac_ll.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -342,6 +342,11 @@ static inline uint32_t emac_ll_transmit_frame_ctrl_status(emac_mac_dev_t *mac_re
     return mac_regs->emacdebug.mactfcs;
 }
 
+static inline uint32_t emac_ll_receive_read_ctrl_state(emac_mac_dev_t *mac_regs)
+{
+    return mac_regs->emacdebug.mtlrfrcs;
+}
+
 /* emacmiidata */
 static inline void emac_ll_set_phy_data(emac_mac_dev_t *mac_regs, uint32_t data)
 {

components/hal/include/hal/emac_hal.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -225,7 +225,7 @@ void emac_hal_start(emac_hal_context_t *hal);
  * @param hal EMAC HAL context infostructure
  * @return
  *     - ESP_OK: succeed
-  *    - ESP_ERR_INVALID_STATE: previous frame transmission is not completed. When this error occurs,
+  *    - ESP_ERR_INVALID_STATE: previous frame transmission/reception is not completed. When this error occurs,
   *      wait and reapeat the EMAC stop again.
  */
 esp_err_t emac_hal_stop(emac_hal_context_t *hal);