From 5917bebcc539d79daf061ce9ee57b9d36b491103 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 14 Nov 2017 11:03:22 +0000 Subject: [PATCH] mcp2515: Use DT-supplied interrupt flags The MCP2515 datasheet clearly describes a level-triggered interrupt pin. Therefore the receiving interrupt controller must also be configured for level-triggered operation otherwise there is a danger of a missed interrupt condition blocking all subsequent interrupts. The ONESHOT flag ensures that the interrupt is masked until the threaded interrupt handler exits. Rather than change the flags globally (they must have worked for at least one user), allow the flags to be overridden from Device Tree in the event that the device has a DT node. See: https://github.com/raspberrypi/linux/issues/2175 https://github.com/raspberrypi/linux/issues/2263 Signed-off-by: Phil Elwell --- arch/arm/boot/dts/overlays/mcp2515-can0-overlay.dts | 2 +- arch/arm/boot/dts/overlays/mcp2515-can1-overlay.dts | 2 +- drivers/net/can/spi/mcp251x.c | 3 +++ 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/arm/boot/dts/overlays/mcp2515-can0-overlay.dts b/arch/arm/boot/dts/overlays/mcp2515-can0-overlay.dts index c96cdae27fb1..03eb5486fa9c 100755 --- a/arch/arm/boot/dts/overlays/mcp2515-can0-overlay.dts +++ b/arch/arm/boot/dts/overlays/mcp2515-can0-overlay.dts @@ -60,7 +60,7 @@ pinctrl-0 = <&can0_pins>; spi-max-frequency = <10000000>; interrupt-parent = <&gpio>; - interrupts = <25 0x2>; + interrupts = <25 8>; /* IRQ_TYPE_LEVEL_LOW */ clocks = <&can0_osc>; }; }; diff --git a/arch/arm/boot/dts/overlays/mcp2515-can1-overlay.dts b/arch/arm/boot/dts/overlays/mcp2515-can1-overlay.dts index 67bd0d9bdaa2..dc773fa3b50c 100644 --- a/arch/arm/boot/dts/overlays/mcp2515-can1-overlay.dts +++ b/arch/arm/boot/dts/overlays/mcp2515-can1-overlay.dts @@ -60,7 +60,7 @@ pinctrl-0 = <&can1_pins>; spi-max-frequency = <10000000>; interrupt-parent = <&gpio>; - interrupts = <25 0x2>; + interrupts = <25 8>; /* IRQ_TYPE_LEVEL_LOW */ clocks = <&can1_osc>; }; }; diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index f3f05fea8e1f..6c2d3aba2591 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -952,6 +952,9 @@ static int mcp251x_open(struct net_device *net) priv->tx_skb = NULL; priv->tx_len = 0; + if (spi->dev.of_node) + flags = 0; + ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist, flags | IRQF_ONESHOT, DEVICE_NAME, priv); if (ret) { -- 2.30.2