Commit 7ba7111b authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

can: rockchip_canfd: rkcanfd_get_berr_counter_corrected(): work around broken... 


can: rockchip_canfd: rkcanfd_get_berr_counter_corrected(): work around broken {RX,TX}ERRORCNT register

Tests show that sometimes both CAN bus error counters read 0x0, even
if the controller is in warning mode
(RKCANFD_REG_STATE_ERROR_WARNING_STATE in RKCANFD_REG_STATE
set).

To work around this issue, if both error counters read from hardware
are 0x0, use the structure priv->bec, otherwise save the read value in
priv->bec.

In rkcanfd_handle_rx_int_one() decrement the priv->bec.rxerr for
successfully RX'ed CAN frames.

In rkcanfd_handle_tx_done_one() decrement the priv->bec.txerr for
successfully TX'ed CAN frames.

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-v5-14-8ae22bcb27cc@pengutronix.de


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 83f9bd6b

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

+44 −6
Original line number Diff line number Diff line
@@ -159,11 +159,47 @@ static int rkcanfd_set_bittiming(struct rkcanfd_priv *priv) 
	return 0;

}



static void rkcanfd_get_berr_counter_raw(struct rkcanfd_priv *priv,

static void rkcanfd_get_berr_counter_corrected(struct rkcanfd_priv *priv,

					       struct can_berr_counter *bec)

{

	struct can_berr_counter bec_raw;

	u32 reg_state;



	bec->rxerr = rkcanfd_read(priv, RKCANFD_REG_RXERRORCNT);

	bec->txerr = rkcanfd_read(priv, RKCANFD_REG_TXERRORCNT);

	bec_raw = *bec;



	/* Tests show that sometimes both CAN bus error counters read

	 * 0x0, even if the controller is in warning mode

	 * (RKCANFD_REG_STATE_ERROR_WARNING_STATE in RKCANFD_REG_STATE

	 * set).

	 *

	 * In case both error counters read 0x0, use the struct

	 * priv->bec, otherwise save the read value to priv->bec.

	 *

	 * rkcanfd_handle_rx_int_one() handles the decrementing of

	 * priv->bec.rxerr for successfully RX'ed CAN frames.

	 *

	 * Luckily the controller doesn't decrement the RX CAN bus

	 * error counter in hardware for self received TX'ed CAN

	 * frames (RKCANFD_REG_MODE_RXSTX_MODE), so RXSTX doesn't

	 * interfere with proper RX CAN bus error counters.

	 *

	 * rkcanfd_handle_tx_done_one() handles the decrementing of

	 * priv->bec.txerr for successfully TX'ed CAN frames.

	 */

	if (!bec->rxerr && !bec->txerr)

		*bec = priv->bec;

	else

		priv->bec = *bec;



	reg_state = rkcanfd_read(priv, RKCANFD_REG_STATE);

	netdev_vdbg(priv->ndev,

		    "%s: Raw/Cor: txerr=%3u/%3u rxerr=%3u/%3u Bus Off=%u Warning=%u\n",

		    __func__,

		    bec_raw.txerr, bec->txerr, bec_raw.rxerr, bec->rxerr,

		    !!(reg_state & RKCANFD_REG_STATE_BUS_OFF_STATE),

		    !!(reg_state & RKCANFD_REG_STATE_ERROR_WARNING_STATE));

}



static int rkcanfd_get_berr_counter(const struct net_device *ndev,
@@ -176,7 +212,7 @@ static int rkcanfd_get_berr_counter(const struct net_device *ndev, 
	if (err)

		return err;



	rkcanfd_get_berr_counter_raw(priv, bec);

	rkcanfd_get_berr_counter_corrected(priv, bec);



	pm_runtime_put(ndev->dev.parent);
@@ -252,6 +288,8 @@ static void rkcanfd_chip_start(struct rkcanfd_priv *priv) 
		RKCANFD_REG_INT_OVERLOAD_INT |

		RKCANFD_REG_INT_TX_FINISH_INT;



	memset(&priv->bec, 0x0, sizeof(priv->bec));



	rkcanfd_chip_fifo_setup(priv);

	rkcanfd_timestamp_init(priv);

	rkcanfd_set_bittiming(priv);
@@ -488,7 +526,7 @@ static int rkcanfd_handle_error_int(struct rkcanfd_priv *priv) 
	if (cf) {

		struct can_berr_counter bec;



		rkcanfd_get_berr_counter_raw(priv, &bec);

		rkcanfd_get_berr_counter_corrected(priv, &bec);

		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR | CAN_ERR_CNT;

		cf->data[6] = bec.txerr;

		cf->data[7] = bec.rxerr;
@@ -517,7 +555,7 @@ static int rkcanfd_handle_state_error_int(struct rkcanfd_priv *priv) 
	u32 timestamp;

	int err;



	rkcanfd_get_berr_counter_raw(priv, &bec);

	rkcanfd_get_berr_counter_corrected(priv, &bec);

	can_state_get_by_berr_counter(ndev, &bec, &tx_state, &rx_state);



	new_state = max(tx_state, rx_state);
@@ -570,7 +608,7 @@ rkcanfd_handle_rx_fifo_overflow_int(struct rkcanfd_priv *priv) 
	if (skb)

		return 0;



	rkcanfd_get_berr_counter_raw(priv, &bec);

	rkcanfd_get_berr_counter_corrected(priv, &bec);



	cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;

	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;

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

+15 −0
Original line number Diff line number Diff line
@@ -167,6 +167,13 @@ static int rkcanfd_rxstx_filter(struct rkcanfd_priv *priv, 


	/* Affected by Erratum 6 */



	/* Manual handling of CAN Bus Error counters. See

	 * rkcanfd_get_corrected_berr_counter() for detailed

	 * explanation.

	 */

	if (priv->bec.txerr)

		priv->bec.txerr--;



	*tx_done = true;



	stats->tx_packets++;
@@ -229,6 +236,14 @@ static int rkcanfd_handle_rx_int_one(struct rkcanfd_priv *priv) 
			return 0;

	}



	/* Manual handling of CAN Bus Error counters. See

	 * rkcanfd_get_corrected_berr_counter() for detailed

	 * explanation.

	 */

	if (priv->bec.rxerr)

		priv->bec.rxerr = min(CAN_ERROR_PASSIVE_THRESHOLD,

				      priv->bec.rxerr) - 1;



	if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_FDF)

		skb = alloc_canfd_skb(priv->ndev, &skb_cfd);

	else

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

+8 −0
Original line number Diff line number Diff line
@@ -113,6 +113,14 @@ void rkcanfd_handle_tx_done_one(struct rkcanfd_priv *priv, const u32 ts, 
	unsigned int tx_tail;



	tx_tail = rkcanfd_get_tx_tail(priv);



	/* Manual handling of CAN Bus Error counters. See

	 * rkcanfd_get_corrected_berr_counter() for detailed

	 * explanation.

	 */

	if (priv->bec.txerr)

		priv->bec.txerr--;



	stats->tx_bytes +=

		can_rx_offload_get_echo_skb_queue_timestamp(&priv->offload,

							    tx_tail, ts,

drivers/net/can/rockchip/rockchip_canfd.h

+2 −0
Original line number Diff line number Diff line
@@ -459,6 +459,8 @@ struct rkcanfd_priv { 
	u32 reg_int_mask_default;

	struct rkcanfd_devtype_data devtype_data;



	struct can_berr_counter bec;



	struct reset_control *reset;

	struct clk_bulk_data *clks;

	int clks_num;