X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fqemu.git;a=blobdiff_plain;f=hw%2Fnet%2Flan9118.c;fp=hw%2Fnet%2Flan9118.c;h=91d81b410b5f9bbb1758616e2eba4358eea855c4;hp=47ff25b4414aaff967fd7200e27c388b74228a41;hb=f243175727903a0d2b52422e7baef86c1838a895;hpb=fee571c7afced9bf4b01b864ea6e85f00fb50e30

diff --git a/hw/net/lan9118.c b/hw/net/lan9118.c
index 47ff25b441..91d81b410b 100644
--- a/hw/net/lan9118.c
+++ b/hw/net/lan9118.c
@@ -150,6 +150,12 @@ do { printf("lan9118: " fmt , ## __VA_ARGS__); } while (0)
 
 #define GPT_TIMER_EN    0x20000000
 
+/*
+ * The MAC Interface Layer (MIL), within the MAC, contains a 2K Byte transmit
+ * and a 128 Byte receive FIFO which is separate from the TX and RX FIFOs.
+ */
+#define MIL_TXFIFO_SIZE         2048
+
 enum tx_state {
     TX_IDLE,
     TX_B,
@@ -166,7 +172,7 @@ typedef struct {
     int32_t pad;
     int32_t fifo_used;
     int32_t len;
-    uint8_t data[2048];
+    uint8_t data[MIL_TXFIFO_SIZE];
 } LAN9118Packet;
 
 static const VMStateDescription vmstate_lan9118_packet = {
@@ -182,7 +188,7 @@ static const VMStateDescription vmstate_lan9118_packet = {
         VMSTATE_INT32(pad, LAN9118Packet),
         VMSTATE_INT32(fifo_used, LAN9118Packet),
         VMSTATE_INT32(len, LAN9118Packet),
-        VMSTATE_UINT8_ARRAY(data, LAN9118Packet, 2048),
+        VMSTATE_UINT8_ARRAY(data, LAN9118Packet, MIL_TXFIFO_SIZE),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -544,7 +550,7 @@ static ssize_t lan9118_receive(NetClientState *nc, const uint8_t *buf,
         return -1;
     }
 
-    if (size >= 2048 || size < 14) {
+    if (size >= MIL_TXFIFO_SIZE || size < 14) {
         return -1;
     }
 
@@ -793,8 +799,22 @@ static void tx_fifo_push(lan9118_state *s, uint32_t val)
             /* Documentation is somewhat unclear on the ordering of bytes
                in FIFO words.  Empirical results show it to be little-endian.
                */
-            /* TODO: FIFO overflow checking.  */
             while (n--) {
+                if (s->txp->len == MIL_TXFIFO_SIZE) {
+                    /*
+                     * No more space in the FIFO. The datasheet is not
+                     * precise about this case. We choose what is easiest
+                     * to model: the packet is truncated, and TXE is raised.
+                     *
+                     * Note, it could be a fragmented packet, but we currently
+                     * do not handle that (see earlier TX_B case).
+                     */
+                    qemu_log_mask(LOG_GUEST_ERROR,
+                                  "MIL TX FIFO overrun, discarding %u byte%s\n",
+                                  n, n > 1 ? "s" : "");
+                    s->int_sts |= TXE_INT;
+                    break;
+                }
                 s->txp->data[s->txp->len] = val & 0xff;
                 s->txp->len++;
                 val >>= 8;