can: flexcan: flexcan_irq_state(): only read timestamp if needed

The function flexcan_irq_state() checks the controller for CAN state
changes and pushes a skb with the new state and a timestamp into the
rx-offload framework.

This patch optimizes the function by only reading the timestamp, if a
state change is detected.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde 2019-10-09 15:15:37 +02:00
parent a4721f27b9
commit 58ed8e77d3

View File

@ -743,8 +743,6 @@ static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
u32 timestamp; u32 timestamp;
int err; int err;
timestamp = priv->read(&regs->timer) << 16;
flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK; flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) { if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ? tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
@ -764,6 +762,8 @@ static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
if (likely(new_state == priv->can.state)) if (likely(new_state == priv->can.state))
return; return;
timestamp = priv->read(&regs->timer) << 16;
skb = alloc_can_err_skb(dev, &cf); skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb)) if (unlikely(!skb))
return; return;