From 58d3cc65a241953d40490329fb7638a93f95dd78 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Fri, 24 Nov 2023 09:27:00 +0100 Subject: [PATCH] can: rockchip_canfd: implement workaround for erratum 6 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. Tested-by: Alibek Omarov Acked-by: Heiko Stuebner Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-12-8ae22bcb27cc@pengutronix.de Signed-off-by: Marc Kleine-Budde --- 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); -- 2.39.5