From 6a07c2305ab200844f250f4dba47ed60d0640505 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 14 Nov 2017 11:03:22 +0000 Subject: [PATCH] can: mcp251x: 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), keep the old behavior for for non DT devices. DT based devices specify the flags in their corresonding DT node. See: https://github.com/raspberrypi/linux/issues/2175 https://github.com/raspberrypi/linux/issues/2263 Signed-off-by: Phil Elwell Tested-by: Sean Nyekjaer Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251x.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index 407c02f2eb8e..fde7509f40c7 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -913,7 +913,7 @@ static int mcp251x_open(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; - unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING; + unsigned long flags = 0; int ret; ret = open_candev(net); @@ -929,6 +929,9 @@ static int mcp251x_open(struct net_device *net) priv->tx_skb = NULL; priv->tx_len = 0; + if (!spi->dev.of_node) + flags = IRQF_TRIGGER_FALLING; + ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist, flags | IRQF_ONESHOT, dev_name(&spi->dev), priv);