The rk3568 CAN-FD errata sheet as of Tue 07 Nov 2023 11:25:31 +08:00
says:
| The CAN controller's transmission of extended frames may
| intermittently change into standard frames.
|
| When using the CAN controller to send extended frames, if the
| 'tx_req' is configured as 1 and coincides with the internal
| transmission point, the extended frame will be transmitted onto the
| bus in the format of a standard frame.
To work around Erratum 6, the driver is in self-receiving mode (RXSTX)
and all received CAN frames are passed through rkcanfd_rxstx_filter().
Add a check in rkcanfd_rxstx_filter() whether the received frame
corresponds to the current outgoing frame, but the extended CAN ID has
been mangled to a standard ID. In this case re-send the original CAN
frame.
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
drivers/net/can/rockchip/rockchip_canfd-rx.c | 44 ++++++++++++++++++++++++++++
drivers/net/can/rockchip/rockchip_canfd-tx.c | 8 +++++
drivers/net/can/rockchip/rockchip_canfd.h | 19 ++++++++++++
3 files changed, 71 insertions(+)
diff --git a/drivers/net/can/rockchip/rockchip_canfd-rx.c b/drivers/net/can/rockchip/rockchip_canfd-rx.c
index 650dfd41e0a0..31cee3362f1e 100644
--- a/drivers/net/can/rockchip/rockchip_canfd-rx.c
+++ b/drivers/net/can/rockchip/rockchip_canfd-rx.c
@@ -95,6 +95,7 @@ static int rkcanfd_rxstx_filter(struct rkcanfd_priv *priv,
const struct canfd_frame *cfd_rx, const u32 ts,
bool *tx_done)
{
+ struct net_device_stats *stats = &priv->ndev->stats;
const struct canfd_frame *cfd_nominal;
const struct sk_buff *skb;
unsigned int tx_tail;
@@ -130,6 +131,49 @@ static int rkcanfd_rxstx_filter(struct rkcanfd_priv *priv,
return 0;
}
+ if (!(priv->devtype_data.quirks & RKCANFD_QUIRK_RK3568_ERRATUM_6))
+ return 0;
+
+ /* Erratum 6: Extended frames may be send as standard frames.
+ *
+ * Not affected if:
+ * - TX'ed a standard frame -or-
+ * - RX'ed an extended frame
+ */
+ if (!(cfd_nominal->can_id & CAN_EFF_FLAG) ||
+ (cfd_rx->can_id & CAN_EFF_FLAG))
+ return 0;
+
+ /* Not affected if:
+ * - standard part and RTR flag of the TX'ed frame
+ * is not equal the CAN-ID and RTR flag of the RX'ed frame.
+ */
+ if ((cfd_nominal->can_id & (CAN_RTR_FLAG | CAN_SFF_MASK)) !=
+ (cfd_rx->can_id & (CAN_RTR_FLAG | CAN_SFF_MASK)))
+ return 0;
+
+ /* Not affected if:
+ * - length is not the same
+ */
+ if (cfd_nominal->len != cfd_rx->len)
+ return 0;
+
+ /* Not affected if:
+ * - the data of non RTR frames is different
+ */
+ if (!(cfd_nominal->can_id & CAN_RTR_FLAG) &&
+ memcmp(cfd_nominal->data, cfd_rx->data, cfd_nominal->len))
+ return 0;
+
+ /* Affected by Erratum 6 */
+
+ *tx_done = true;
+
+ stats->tx_packets++;
+ stats->tx_errors++;
+
+ rkcanfd_xmit_retry(priv);
+
return 0;
}
diff --git a/drivers/net/can/rockchip/rockchip_canfd-tx.c b/drivers/net/can/rockchip/rockchip_canfd-tx.c
index 668a902f4c2a..e98e7a836b83 100644
--- a/drivers/net/can/rockchip/rockchip_canfd-tx.c
+++ b/drivers/net/can/rockchip/rockchip_canfd-tx.c
@@ -14,6 +14,14 @@ static void rkcanfd_start_xmit_write_cmd(const struct rkcanfd_priv *priv,
rkcanfd_write(priv, RKCANFD_REG_CMD, reg_cmd);
}
+void rkcanfd_xmit_retry(struct rkcanfd_priv *priv)
+{
+ const unsigned int tx_head = rkcanfd_get_tx_head(priv);
+ const u32 reg_cmd = RKCANFD_REG_CMD_TX_REQ(tx_head);
+
+ rkcanfd_start_xmit_write_cmd(priv, reg_cmd);
+}
+
int rkcanfd_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
struct rkcanfd_priv *priv = netdev_priv(ndev);
diff --git a/drivers/net/can/rockchip/rockchip_canfd.h b/drivers/net/can/rockchip/rockchip_canfd.h
index a4688411e586..3fe6ddcdd8ac 100644
--- a/drivers/net/can/rockchip/rockchip_canfd.h
+++ b/drivers/net/can/rockchip/rockchip_canfd.h
@@ -342,6 +342,24 @@
/* Erratum 6: The CAN controller's transmission of extended frames may
* intermittently change into standard frames
+ *
+ * Work around this issue by activating self reception (RXSTX). If we
+ * have pending TX CAN frames, check all RX'ed CAN frames in
+ * rkcanfd_rxstx_filter().
+ *
+ * If it's a frame we've send and it's OK, call the TX complete
+ * handler: rkcanfd_handle_tx_done_one(). Mask the TX complete IRQ.
+ *
+ * If it's a frame we've send, but the CAN-ID is mangled, resend the
+ * original extended frame.
+ *
+ * To reproduce:
+ * host:
+ * canfdtest -evx -g can0
+ * candump any,0:80000000 -cexdtA
+ * dut:
+ * canfdtest -evx can0
+ * ethtool -S can0
*/
#define RKCANFD_QUIRK_RK3568_ERRATUM_6 BIT(5)
@@ -499,6 +517,7 @@ int rkcanfd_handle_rx_int(struct rkcanfd_priv *priv);
void rkcanfd_timestamp_init(struct rkcanfd_priv *priv);
+void rkcanfd_xmit_retry(struct rkcanfd_priv *priv);
int rkcanfd_start_xmit(struct sk_buff *skb, struct net_device *ndev);
void rkcanfd_handle_tx_done_one(struct rkcanfd_priv *priv, const u32 ts,
unsigned int *frame_len_p);
--
2.45.2
