1 files changed, 32 insertions, 26 deletions

diff --git a/hw/net/allwinner-sun8i-emac.c b/hw/net/allwinner-sun8i-emac.c
index bf91803d65..ff611f18fb 100644
--- a/hw/net/allwinner-sun8i-emac.c
+++ b/hw/net/allwinner-sun8i-emac.c
@@ -339,35 +339,40 @@ static void allwinner_sun8i_emac_update_irq(AwSun8iEmacState *s)
     qemu_set_irq(s->irq, (s->int_sta & s->int_en) != 0);
 }
 
-static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s,
-                                               FrameDescriptor *desc,
-                                               size_t min_size)
+static bool allwinner_sun8i_emac_desc_owned(FrameDescriptor *desc,
+                                            size_t min_buf_size)
 {
-    uint32_t paddr = desc->next;
+    return (desc->status & DESC_STATUS_CTL) && (min_buf_size == 0 ||
+           (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >= min_buf_size);
+}
 
-    dma_memory_read(&s->dma_as, paddr, desc, sizeof(*desc));
+static void allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s,
+                                          FrameDescriptor *desc,
+                                          uint32_t phys_addr)
+{
+    dma_memory_read(&s->dma_as, phys_addr, desc, sizeof(*desc));
+}
 
-    if ((desc->status & DESC_STATUS_CTL) &&
-        (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >= min_size) {
-        return paddr;
-    } else {
-        return 0;
-    }
+static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s,
+                                               FrameDescriptor *desc)
+{
+    const uint32_t nxt = desc->next;
+    allwinner_sun8i_emac_get_desc(s, desc, nxt);
+    return nxt;
 }
 
-static uint32_t allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s,
-                                              FrameDescriptor *desc,
-                                              uint32_t start_addr,
-                                              size_t min_size)
+static uint32_t allwinner_sun8i_emac_find_desc(AwSun8iEmacState *s,
+                                               FrameDescriptor *desc,
+                                               uint32_t start_addr,
+                                               size_t min_size)
 {
     uint32_t desc_addr = start_addr;
 
     /* Note that the list is a cycle. Last entry points back to the head. */
     while (desc_addr != 0) {
-        dma_memory_read(&s->dma_as, desc_addr, desc, sizeof(*desc));
+        allwinner_sun8i_emac_get_desc(s, desc, desc_addr);
 
-        if ((desc->status & DESC_STATUS_CTL) &&
-            (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >= min_size) {
+        if (allwinner_sun8i_emac_desc_owned(desc, min_size)) {
             return desc_addr;
         } else if (desc->next == start_addr) {
             break;
@@ -383,14 +388,14 @@ static uint32_t allwinner_sun8i_emac_rx_desc(AwSun8iEmacState *s,
                                              FrameDescriptor *desc,
                                              size_t min_size)
 {
-    return allwinner_sun8i_emac_get_desc(s, desc, s->rx_desc_curr, min_size);
+    return allwinner_sun8i_emac_find_desc(s, desc, s->rx_desc_curr, min_size);
 }
 
 static uint32_t allwinner_sun8i_emac_tx_desc(AwSun8iEmacState *s,
-                                             FrameDescriptor *desc,
-                                             size_t min_size)
+                                             FrameDescriptor *desc)
 {
-    return allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_head, min_size);
+    allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_curr);
+    return s->tx_desc_curr;
 }
 
 static void allwinner_sun8i_emac_flush_desc(AwSun8iEmacState *s,
@@ -470,7 +475,8 @@ static ssize_t allwinner_sun8i_emac_receive(NetClientState *nc,
         bytes_left -= desc_bytes;
 
         /* Move to the next descriptor */
-        s->rx_desc_curr = allwinner_sun8i_emac_next_desc(s, &desc, 64);
+        s->rx_desc_curr = allwinner_sun8i_emac_find_desc(s, &desc, desc.next,
+                                                         AW_SUN8I_EMAC_MIN_PKT_SZ);
         if (!s->rx_desc_curr) {
             /* Not enough buffer space available */
             s->int_sta |= INT_STA_RX_BUF_UA;
@@ -495,10 +501,10 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacState *s)
     size_t transmitted = 0;
     static uint8_t packet_buf[2048];
 
-    s->tx_desc_curr = allwinner_sun8i_emac_tx_desc(s, &desc, 0);
+    s->tx_desc_curr = allwinner_sun8i_emac_tx_desc(s, &desc);
 
     /* Read all transmit descriptors */
-    while (s->tx_desc_curr != 0) {
+    while (allwinner_sun8i_emac_desc_owned(&desc, 0)) {
 
         /* Read from physical memory into packet buffer */
         bytes = desc.status2 & DESC_STATUS2_BUF_SIZE_MASK;
@@ -524,7 +530,7 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacState *s)
             packet_bytes = 0;
             transmitted++;
         }
-        s->tx_desc_curr = allwinner_sun8i_emac_next_desc(s, &desc, 0);
+        s->tx_desc_curr = allwinner_sun8i_emac_next_desc(s, &desc);
     }
 
     /* Raise transmit completed interrupt */