From 623c500d1571b7169ad683ad94fe8835023395a5 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 14 Nov 2017 11:03:22 +0000 Subject: [PATCH 132/454] 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 --- drivers/net/can/spi/mcp251x.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -951,6 +951,9 @@ static int mcp251x_open(struct net_devic 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) {