return 0;
}
-static int
-mcp251xfd_handle_tefif_recover(const struct mcp251xfd_priv *priv, const u32 seq)
-{
- const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
- u32 tef_sta;
- int err;
-
- err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFSTA, &tef_sta);
- if (err)
- return err;
-
- if (tef_sta & MCP251XFD_REG_TEFSTA_TEFOVIF) {
- netdev_err(priv->ndev,
- "Transmit Event FIFO buffer overflow.\n");
- return -ENOBUFS;
- }
-
- netdev_info(priv->ndev,
- "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x).\n",
- tef_sta & MCP251XFD_REG_TEFSTA_TEFFIF ?
- "full" : tef_sta & MCP251XFD_REG_TEFSTA_TEFNEIF ?
- "not empty" : "empty",
- seq, priv->tef->tail, priv->tef->head, tx_ring->head);
-
- /* The Sequence Number in the TEF doesn't match our tef_tail. */
- return -EAGAIN;
-}
-
static int
mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
const struct mcp251xfd_hw_tef_obj *hw_tef_obj,
unsigned int *frame_len_ptr)
{
struct net_device_stats *stats = &priv->ndev->stats;
+ u32 seq, tef_tail_masked, tef_tail;
struct sk_buff *skb;
- u32 seq, seq_masked, tef_tail_masked, tef_tail;
- seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
+ /* Use the MCP2517FD mask on the MCP2518FD, too. We only
+ * compare 7 bits, this is enough to detect old TEF objects.
+ */
+ seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK,
hw_tef_obj->flags);
-
- /* Use the MCP2517FD mask on the MCP2518FD, too. We only
- * compare 7 bits, this should be enough to detect
- * net-yet-completed, i.e. old TEF objects.
- */
- seq_masked = seq &
- field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
tef_tail_masked = priv->tef->tail &
field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
- if (seq_masked != tef_tail_masked)
- return mcp251xfd_handle_tefif_recover(priv, seq);
+
+ /* According to mcp2518fd erratum DS80000789E 6. the FIFOCI
+ * bits of a FIFOSTA register, here the TX FIFO tail index
+ * might be corrupted and we might process past the TEF FIFO's
+ * head into old CAN frames.
+ *
+ * Compare the sequence number of the currently processed CAN
+ * frame with the expected sequence number. Abort with
+ * -EBADMSG if an old CAN frame is detected.
+ */
+ if (seq != tef_tail_masked) {
+ netdev_dbg(priv->ndev, "%s: chip=0x%02x ring=0x%02x\n", __func__,
+ seq, tef_tail_masked);
+ stats->tx_fifo_errors++;
+
+ return -EBADMSG;
+ }
tef_tail = mcp251xfd_get_tef_tail(priv);
skb = priv->can.echo_skb[tef_tail];
unsigned int frame_len = 0;
err = mcp251xfd_handle_tefif_one(priv, &hw_tef_obj[i], &frame_len);
- /* -EAGAIN means the Sequence Number in the TEF
- * doesn't match our tef_tail. This can happen if we
- * read the TEF objects too early. Leave loop let the
- * interrupt handler call us again.
+ /* -EBADMSG means we're affected by mcp2518fd erratum
+ * DS80000789E 6., i.e. the Sequence Number in the TEF
+ * doesn't match our tef_tail. Don't process any
+ * further and mark processed frames as good.
*/
- if (err == -EAGAIN)
+ if (err == -EBADMSG)
goto out_netif_wake_queue;
if (err)
return err;