Commit bed11db3 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Marc Kleine-Budde
Browse files

can: c_can: Fix startup logic 



c_can_start() enables interrupts way too early. The first enabling
happens when setting the control mode in c_can_chip_config() and then
again at the end of the function.

But that happens before napi_enable() and that means that an interrupt
which comes in will disable interrupts again and call napi_schedule,
which ignores the request and the later napi_enable() is not making
thinks work either. So the interface is up with all device interrupts
disabled.

Move the device interrupt after napi_enable() and add it to the other
callsites of c_can_start() in c_can_set_mode() and c_can_power_up()

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 129eef21

drivers/net/can/c_can/c_can.c

+17 −18
Original line number Diff line number Diff line
@@ -612,30 +612,22 @@ static int c_can_chip_config(struct net_device *dev) 
	struct c_can_priv *priv = netdev_priv(dev);



	/* enable automatic retransmission */

	priv->write_reg(priv, C_CAN_CTRL_REG,

			CONTROL_ENABLE_AR);

	priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR);



	if ((priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) &&

	    (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)) {

		/* loopback + silent mode : useful for hot self-test */

		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |

				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);

		priv->write_reg(priv, C_CAN_TEST_REG,

				TEST_LBACK | TEST_SILENT);

		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST);

		priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK | TEST_SILENT);

	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {

		/* loopback mode : useful for self-test function */

		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |

				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);

		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST);

		priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK);

	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {

		/* silent mode : bus-monitoring mode */

		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |

				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);

		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST);

		priv->write_reg(priv, C_CAN_TEST_REG, TEST_SILENT);

	} else

		/* normal mode*/

		priv->write_reg(priv, C_CAN_CTRL_REG,

				CONTROL_EIE | CONTROL_SIE | CONTROL_IE);

	}



	/* configure message objects */

	c_can_configure_msg_objects(dev);
@@ -662,9 +654,6 @@ static int c_can_start(struct net_device *dev) 
	/* reset tx helper pointers */

	priv->tx_next = priv->tx_echo = 0;



	/* enable status change, error and module interrupts */

	c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);



	return 0;

}
@@ -681,6 +670,7 @@ static void c_can_stop(struct net_device *dev) 


static int c_can_set_mode(struct net_device *dev, enum can_mode mode)

{

	struct c_can_priv *priv = netdev_priv(dev);

	int err;



	switch (mode) {
@@ -689,6 +679,8 @@ static int c_can_set_mode(struct net_device *dev, enum can_mode mode) 
		if (err)

			return err;

		netif_wake_queue(dev);

		/* enable status change, error and module interrupts */

		c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);

		break;

	default:

		return -EOPNOTSUPP;
@@ -1184,6 +1176,8 @@ static int c_can_open(struct net_device *dev) 
	can_led_event(dev, CAN_LED_EVENT_OPEN);



	napi_enable(&priv->napi);

	/* enable status change, error and module interrupts */

	c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);

	netif_start_queue(dev);



	return 0;
@@ -1281,6 +1275,7 @@ int c_can_power_up(struct net_device *dev) 
	u32 val;

	unsigned long time_out;

	struct c_can_priv *priv = netdev_priv(dev);

	int ret;



	if (!(dev->flags & IFF_UP))

		return 0;
@@ -1307,7 +1302,11 @@ int c_can_power_up(struct net_device *dev) 
	if (time_after(jiffies, time_out))

		return -ETIMEDOUT;



	return c_can_start(dev);

	ret = c_can_start(dev);

	if (!ret)

		c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);



	return ret;

}

EXPORT_SYMBOL_GPL(c_can_power_up);

#endif

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