can: c_can: fix an interrupt thrash issue with c_can driver

[android-x86/kernel.git] / drivers / net / can / c_can / c_can.c

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 7e5cc0b..227dfd8 100644 (file)
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -688,7 +688,7 @@ static int c_can_get_berr_counter(const struct net_device *dev,
  *
  * We iterate from priv->tx_echo to priv->tx_next and check if the
  * packet has been transmitted, echo it back to the CAN framework.
- * If we discover a not yet transmitted package, stop looking for more.
+ * If we discover a not yet transmitted packet, stop looking for more.
  */
 static void c_can_do_tx(struct net_device *dev)
 {
@@ -700,7 +700,7 @@ static void c_can_do_tx(struct net_device *dev)
        for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
                msg_obj_no = get_tx_echo_msg_obj(priv);
                val = c_can_read_reg32(priv, &priv->regs->txrqst1);
-               if (!(val & (1 << msg_obj_no))) {
+               if (!(val & (1 << (msg_obj_no - 1)))) {
                        can_get_echo_skb(dev,
                                        msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
                        stats->tx_bytes += priv->read_reg(priv,
@@ -708,6 +708,8 @@ static void c_can_do_tx(struct net_device *dev)
                                        & IF_MCONT_DLC_MASK;
                        stats->tx_packets++;
                        c_can_inval_msg_object(dev, 0, msg_obj_no);
+               } else {
+                       break;
                }
        }
 
@@ -952,7 +954,7 @@ static int c_can_poll(struct napi_struct *napi, int quota)
        struct net_device *dev = napi->dev;
        struct c_can_priv *priv = netdev_priv(dev);
 
-       irqstatus = priv->read_reg(priv, &priv->regs->interrupt);
+       irqstatus = priv->irqstatus;
        if (!irqstatus)
                goto end;
 
@@ -1030,12 +1032,11 @@ end:
 
 static irqreturn_t c_can_isr(int irq, void *dev_id)
 {
-       u16 irqstatus;
        struct net_device *dev = (struct net_device *)dev_id;
        struct c_can_priv *priv = netdev_priv(dev);
 
-       irqstatus = priv->read_reg(priv, &priv->regs->interrupt);
-       if (!irqstatus)
+       priv->irqstatus = priv->read_reg(priv, &priv->regs->interrupt);
+       if (!priv->irqstatus)
                return IRQ_NONE;
 
        /* disable all interrupts and schedule the NAPI */