can: flexcan: flexcan_irq_state(): only read timestamp if needed (58ed8e77) · Commits · 戴 / test

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>

drivers/net/can/flexcan.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -743,8 +743,6 @@ static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
		u32 timestamp;
		int err;

		timestamp = priv->read(&regs->timer) << 16;

		flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
		if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
		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))
		return;

		timestamp = priv->read(&regs->timer) << 16;

		skb = alloc_can_err_skb(dev, &cf);
		if (unlikely(!skb))
		return;

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