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: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index a5c8dcf..b1629a4 100644 (file)
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -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