Commit 58d3cc65 authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

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: default avatarAlibek Omarov <a1ba.omarov@gmail.com>
Acked-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-12-8ae22bcb27cc@pengutronix.de


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent b6661d73

drivers/net/can/rockchip/rockchip_canfd-rx.c

+44 −0
Original line number Diff line number Diff line
@@ -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;

}

drivers/net/can/rockchip/rockchip_canfd-tx.c

+8 −0
Original line number Diff line number Diff line
@@ -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);

drivers/net/can/rockchip/rockchip_canfd.h

+19 −0
Original line number Diff line number Diff line
@@ -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);