From 1a92e5a9109963e2491eec111b84b35b4e2adc8f Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 9 Oct 2019 15:15:37 +0200 Subject: [PATCH] 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 --- drivers/net/can/flexcan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -751,8 +751,6 @@ static void flexcan_irq_state(struct net u32 timestamp; int err; - timestamp = priv->read(®s->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) ? @@ -772,6 +770,8 @@ static void flexcan_irq_state(struct net if (likely(new_state == priv->can.state)) return; + timestamp = priv->read(®s->timer) << 16; + skb = alloc_can_err_skb(dev, &cf); if (unlikely(!skb)) return;