Commit 9df2faf9 authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

can: at91_can: at91_irq_err_line(): make use of can_change_state() and can_bus_off() 

The driver implements a hand crafted CAN state handling. Update the
driver to make use of can_change_state(), introduced in ("can: dev:
Consolidate and unify state change handling")

Also switch from hand crafted CAN bus off handling to can_bus_off():
In case of a bus off, abort all pending TX requests, switch off the
device and let can_bus_off() handle the device restart.

Link: https://lore.kernel.org/all/20231005-at91_can-rx_offload-v2-24-9987d53600e0@pengutronix.de


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent f13e8699

drivers/net/can/at91_can.c

+21 −110
Original line number Diff line number Diff line
@@ -443,7 +443,7 @@ static void at91_chip_start(struct net_device *dev) 
	at91_read(priv, AT91_SR);



	/* Enable interrupts */

	reg_ier = get_irq_mb_rx(priv) | AT91_IRQ_ERRP | AT91_IRQ_ERR_FRAME;

	reg_ier = get_irq_mb_rx(priv) | AT91_IRQ_ERR_LINE | AT91_IRQ_ERR_FRAME;

	at91_write(priv, AT91_IER, reg_ier);

}
@@ -452,6 +452,11 @@ static void at91_chip_stop(struct net_device *dev, enum can_state state) 
	struct at91_priv *priv = netdev_priv(dev);

	u32 reg_mr;



	/* Abort any pending TX requests. However this doesn't seem to

	 * work in case of bus-off on sama5d3.

	 */

	at91_write(priv, AT91_ACR, get_irq_mb_tx(priv));



	/* disable interrupts */

	at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
@@ -832,111 +837,6 @@ static void at91_irq_tx(struct net_device *dev, u32 reg_sr) 
		netif_wake_queue(dev);

}



static void at91_irq_err_state(struct net_device *dev,

			       struct can_frame *cf, enum can_state new_state)

{

	struct at91_priv *priv = netdev_priv(dev);

	u32 reg_idr = 0, reg_ier = 0;

	struct can_berr_counter bec;



	at91_get_berr_counter(dev, &bec);



	switch (priv->can.state) {

	case CAN_STATE_ERROR_ACTIVE:

		/* from: ERROR_ACTIVE

		 * to  : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF

		 * =>  : there was a warning int

		 */

		if (new_state >= CAN_STATE_ERROR_WARNING &&

		    new_state <= CAN_STATE_BUS_OFF) {

			netdev_dbg(dev, "Error Warning IRQ\n");

			priv->can.can_stats.error_warning++;



			cf->can_id |= CAN_ERR_CRTL;

			cf->data[1] = (bec.txerr > bec.rxerr) ?

				CAN_ERR_CRTL_TX_WARNING :

				CAN_ERR_CRTL_RX_WARNING;

		}

		fallthrough;

	case CAN_STATE_ERROR_WARNING:

		/* from: ERROR_ACTIVE, ERROR_WARNING

		 * to  : ERROR_PASSIVE, BUS_OFF

		 * =>  : error passive int

		 */

		if (new_state >= CAN_STATE_ERROR_PASSIVE &&

		    new_state <= CAN_STATE_BUS_OFF) {

			netdev_dbg(dev, "Error Passive IRQ\n");

			priv->can.can_stats.error_passive++;



			cf->can_id |= CAN_ERR_CRTL;

			cf->data[1] = (bec.txerr > bec.rxerr) ?

				CAN_ERR_CRTL_TX_PASSIVE :

				CAN_ERR_CRTL_RX_PASSIVE;

		}

		break;

	case CAN_STATE_BUS_OFF:

		/* from: BUS_OFF

		 * to  : ERROR_ACTIVE, ERROR_WARNING, ERROR_PASSIVE

		 */

		if (new_state <= CAN_STATE_ERROR_PASSIVE) {

			cf->can_id |= CAN_ERR_RESTARTED;



			netdev_dbg(dev, "restarted\n");

			priv->can.can_stats.restarts++;



			netif_carrier_on(dev);

			netif_wake_queue(dev);

		}

		break;

	default:

		break;

	}



	/* process state changes depending on the new state */

	switch (new_state) {

	case CAN_STATE_ERROR_ACTIVE:

		/* actually we want to enable AT91_IRQ_WARN here, but

		 * it screws up the system under certain

		 * circumstances. so just enable AT91_IRQ_ERRP, thus

		 * the "fallthrough"

		 */

		netdev_dbg(dev, "Error Active\n");

		cf->can_id |= CAN_ERR_PROT;

		cf->data[2] = CAN_ERR_PROT_ACTIVE;

		fallthrough;

	case CAN_STATE_ERROR_WARNING:

		reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_BOFF;

		reg_ier = AT91_IRQ_ERRP;

		break;

	case CAN_STATE_ERROR_PASSIVE:

		reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_ERRP;

		reg_ier = AT91_IRQ_BOFF;

		break;

	case CAN_STATE_BUS_OFF:

		reg_idr = AT91_IRQ_ERRA | AT91_IRQ_ERRP |

			AT91_IRQ_WARN | AT91_IRQ_BOFF;

		reg_ier = 0;



		cf->can_id |= CAN_ERR_BUSOFF;



		netdev_dbg(dev, "bus-off\n");

		netif_carrier_off(dev);

		priv->can.can_stats.bus_off++;



		/* turn off chip, if restart is disabled */

		if (!priv->can.restart_ms) {

			at91_chip_stop(dev, CAN_STATE_BUS_OFF);

			return;

		}

		break;

	default:

		break;

	}



	at91_write(priv, AT91_IDR, reg_idr);

	at91_write(priv, AT91_IER, reg_ier);

}



static void at91_irq_err_line(struct net_device *dev, const u32 reg_sr)

{

	enum can_state new_state, rx_state, tx_state;
@@ -970,15 +870,22 @@ static void at91_irq_err_line(struct net_device *dev, const u32 reg_sr) 
	if (likely(new_state == priv->can.state))

		return;



	/* The skb allocation might fail, but can_change_state()

	 * handles cf == NULL.

	 */

	skb = alloc_can_err_skb(dev, &cf);

	can_change_state(dev, cf, tx_state, rx_state);



	if (new_state == CAN_STATE_BUS_OFF) {

		at91_chip_stop(dev, CAN_STATE_BUS_OFF);

		can_bus_off(dev);

	}



	if (unlikely(!skb))

		return;



	at91_irq_err_state(dev, cf, new_state);



	netif_rx(skb);



	priv->can.state = new_state;

}



static void at91_irq_err_frame(struct net_device *dev, const u32 reg_sr)
@@ -1072,7 +979,11 @@ static irqreturn_t at91_irq(int irq, void *dev_id) 
	if (reg_sr & get_irq_mb_tx(priv))

		at91_irq_tx(dev, reg_sr);



	/* Line Error interrupt */

	if (reg_sr & AT91_IRQ_ERR_LINE ||

	    priv->can.state > CAN_STATE_ERROR_ACTIVE) {

		at91_irq_err_line(dev, reg_sr);

	}



	/* Frame Error Interrupt */

	if (reg_sr & AT91_IRQ_ERR_FRAME)