sam0_eth: implement .confirm_send() to fix fragmented sending

cpu/sam0_common/Makefile.dep

@@ -20,7 +20,7 @@ USEMODULE += sam0_common_periph
 ifneq (,$(filter sam0_eth,$(USEMODULE)))
   USEMODULE += iolist
   USEMODULE += netdev_eth
-  USEMODULE += netdev_legacy_api
+  USEMODULE += netdev_new_api
   USEMODULE += netopt
   FEATURES_REQUIRED += periph_eth
   FEATURES_REQUIRED += periph_gpio_irq

cpu/sam0_common/include/periph_cpu_common.h

@@ -946,7 +946,7 @@ typedef enum {
 #endif
 
 #ifndef ETH_TX_BUFFER_COUNT
-#define ETH_TX_BUFFER_COUNT (4)
+#define ETH_TX_BUFFER_COUNT (2)
 #endif
 
 #ifndef ETH_RX_BUFFER_SIZE

cpu/sam0_common/periph/eth.c

@@ -78,8 +78,8 @@
 /* GMAC buffer descriptors */
 #define GMAC_DESC_ALIGNMENT 8
 #define GMAC_BUF_ALIGNMENT  32
 static struct eth_buf_desc rx_desc[ETH_RX_BUFFER_COUNT] __attribute__((aligned(GMAC_DESC_ALIGNMENT)));
 static struct eth_buf_desc tx_desc[ETH_TX_BUFFER_COUNT] __attribute__((aligned(GMAC_DESC_ALIGNMENT)));
 
 static struct eth_buf_desc *rx_curr;
 static struct eth_buf_desc *tx_curr;
@@ -89,8 +89,8 @@
 static uint8_t  tx_idx;
 static uint8_t  rx_idx;
 
 static uint8_t  rx_buf[ETH_RX_BUFFER_COUNT][ETH_RX_BUFFER_SIZE] __attribute__((aligned(GMAC_BUF_ALIGNMENT)));
 static uint8_t  tx_buf[ETH_TX_BUFFER_COUNT][ETH_TX_BUFFER_SIZE] __attribute__((aligned(GMAC_BUF_ALIGNMENT)));
 extern sam0_eth_netdev_t _sam0_eth_dev;
 
 static bool _is_sleeping;
@@ -237,14 +237,16 @@
     }
     if (len == tx_len) {
         /* Clear and set the frame size */
-        tx_curr->status &= ~DESC_TX_STATUS_LEN_MASK;
-        tx_curr->status |= (len & DESC_TX_STATUS_LEN_MASK);
+        tx_curr->status = (len & DESC_TX_STATUS_LEN_MASK)
         /* Indicate this is the last buffer and the frame is ready */
-        tx_curr->status |= DESC_TX_STATUS_LAST_BUF | DESC_TX_STATUS_USED;
+                        | DESC_TX_STATUS_LAST_BUF;
         /* Prepare next buffer index */
-        tx_idx = (tx_idx < ETH_TX_BUFFER_COUNT-1) ? tx_idx+1 : 0;
-        __DSB();
-        tx_curr->status &= ~DESC_TX_STATUS_USED;
+        if (++tx_idx == ETH_TX_BUFFER_COUNT) {
+            /* Set WRAP flag to indicate last buffer */
+            tx_curr->status |= DESC_TX_STATUS_WRAP;
+            tx_idx = 0;
+        }
+        __DMB();
         /* Start transmission */
         GMAC->NCR.reg |= GMAC_NCR_TSTART;
         /* Set the next buffer */
@@ -256,6 +258,12 @@
     return len;
 }
 
+unsigned _sam0_eth_get_last_len(void)
+{
+    unsigned idx = tx_idx ? tx_idx - 1 : ETH_TX_BUFFER_COUNT - 1;
+    return tx_desc[idx].status & DESC_TX_STATUS_LEN_MASK;
+}
+
 static int _try_receive(char* data, unsigned max_len, int block)
 {
     (void)block;
@@ -382,8 +390,10 @@
     GMAC->IDR.reg = 0xFFFFFFFF;
     /* clear flags */
     GMAC->RSR.reg = GMAC_RSR_HNO | GMAC_RSR_RXOVR | GMAC_RSR_REC | GMAC_RSR_BNA;
+    GMAC->TSR.reg = 0xFFFF;
     /* Enable needed interrupts */
-    GMAC->IER.reg = GMAC_IER_RCOMP;
+    GMAC->IER.reg = GMAC_IER_RCOMP
+                  | GMAC_IER_TCOMP | GMAC_IER_TFC | GMAC_IER_RLEX;
 
     GMAC->NCFGR.reg = GMAC_NCFGR_MTIHEN
                     | GMAC_NCFGR_RXCOEN | GMAC_NCFGR_MAXFS | GMAC_NCFGR_CAF

cpu/sam0_common/sam0_eth/eth-netdev.c

@@ -205,10 +205,36 @@ static int _sam0_eth_send(netdev_t *netdev, const iolist_t *iolist)
         /* TODO: use a specific netdev callback here ? */
         return -EOVERFLOW;
     }
-    netdev->event_callback(netdev, NETDEV_EVENT_TX_COMPLETE);
     return ret;
 }
 
+static int _sam0_eth_confirm_send(netdev_t *netdev, void *info)
+{
+    (void)netdev;
+    (void)info;
+
+    uint32_t tsr = GMAC->TSR.reg;
+    GMAC->TSR.reg = tsr; /* clear flags */
+
+    /* transmit is active */
+    if (tsr & GMAC_TSR_TXGO) {
+        return -EAGAIN;
+    }
+
+    /* Retry Limit Exceeded */
+    if (tsr & GMAC_TSR_RLE) {
+        return -EBUSY;
+    }
+
+    /* Transmit Frame Corruption, Collision Occurred */
+    if (tsr & (GMAC_TSR_TFC | GMAC_TSR_COL)) {
+        return -EIO;
+    }
+
+    extern unsigned _sam0_eth_get_last_len(void);
+    return _sam0_eth_get_last_len();
+}
+
 static int _sam0_eth_get(netdev_t *netdev, netopt_t opt, void *val, size_t max_len)
 {
     int res = -1;
@@ -278,6 +304,7 @@ static int _sam0_eth_set(netdev_t *netdev, netopt_t opt, const void *val, size_t
 static const netdev_driver_t _sam0_eth_driver =
 {
     .send = _sam0_eth_send,
+    .confirm_send = _sam0_eth_confirm_send,
     .recv = _sam0_eth_recv,
     .init = _sam0_eth_init,
     .isr  = _sam0_eth_isr,
@@ -301,15 +328,21 @@ void isr_gmac(void)
 {
     uint32_t isr;
     uint32_t rsr;
+    netdev_t* netdev = _sam0_eth_dev.netdev;
 
     isr = GMAC->ISR.reg;
     rsr = GMAC->RSR.reg;
-    (void)isr;
+
+    /* TX done, signal it to netdev */
+    if (isr & GMAC_ISR_TCOMP) {
+        netdev->event_callback(netdev, NETDEV_EVENT_TX_COMPLETE);
+    }
 
     /* New frame received, signal it to netdev */
     if (rsr & GMAC_RSR_REC) {
-        netdev_trigger_event_isr(_sam0_eth_dev.netdev);
+        netdev_trigger_event_isr(netdev);
     }
+
     /* Buffers Not Available, this can occur if there is a heavy traffic
        on the network. In this case, disable the GMAC reception, flush
        our internal buffers and re-enable the reception. This will drop