| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | From 1a92e5a9109963e2491eec111b84b35b4e2adc8f Mon Sep 17 00:00:00 2001 |
| 2 | From: Marc Kleine-Budde <mkl@pengutronix.de> |
| 3 | Date: Wed, 9 Oct 2019 15:15:37 +0200 |
| 4 | Subject: [PATCH] can: flexcan: flexcan_irq_state(): only read timestamp if |
| 5 | needed |
| 6 | |
| 7 | The function flexcan_irq_state() checks the controller for CAN state |
| 8 | changes and pushes a skb with the new state and a timestamp into the |
| 9 | rx-offload framework. |
| 10 | |
| 11 | This patch optimizes the function by only reading the timestamp, if a |
| 12 | state change is detected. |
| 13 | |
| 14 | Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| 15 | --- |
| 16 | drivers/net/can/flexcan.c | 4 ++-- |
| 17 | 1 file changed, 2 insertions(+), 2 deletions(-) |
| 18 | |
| 19 | --- a/drivers/net/can/flexcan.c |
| 20 | +++ b/drivers/net/can/flexcan.c |
| 21 | @@ -751,8 +751,6 @@ static void flexcan_irq_state(struct net |
| 22 | u32 timestamp; |
| 23 | int err; |
| 24 | |
| 25 | - timestamp = priv->read(®s->timer) << 16; |
| 26 | - |
| 27 | flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK; |
| 28 | if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) { |
| 29 | tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ? |
| 30 | @@ -772,6 +770,8 @@ static void flexcan_irq_state(struct net |
| 31 | if (likely(new_state == priv->can.state)) |
| 32 | return; |
| 33 | |
| 34 | + timestamp = priv->read(®s->timer) << 16; |
| 35 | + |
| 36 | skb = alloc_can_err_skb(dev, &cf); |
| 37 | if (unlikely(!skb)) |
| 38 | return; |