layerscape: add patches-5.4

[openwrt/staging/wigyori.git] / target / linux / layerscape / patches-5.4 / 802-can-0008-can-flexcan-flexcan_irq_state-only-read-timestamp-if.patch

diff --git a/target/linux/layerscape/patches-5.4/802-can-0008-can-flexcan-flexcan_irq_state-only-read-timestamp-if.patch b/target/linux/layerscape/patches-5.4/802-can-0008-can-flexcan-flexcan_irq_state-only-read-timestamp-if.patch
new file mode 100644 (file)
index 0000000..bc84f5f
--- /dev/null
+++ b/target/linux/layerscape/patches-5.4/802-can-0008-can-flexcan-flexcan_irq_state-only-read-timestamp-if.patch
@@ -0,0 +1,38 @@
+From 1a92e5a9109963e2491eec111b84b35b4e2adc8f Mon Sep 17 00:00:00 2001
+From: Marc Kleine-Budde <mkl@pengutronix.de>
+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 <mkl@pengutronix.de>
+---
+ 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
+@@ -744,8 +744,6 @@ static void flexcan_irq_state(struct net
+       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) ?
+@@ -765,6 +763,8 @@ static void flexcan_irq_state(struct net
+       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;