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-rw-r--r--target/linux/bcm27xx/patches-4.19/950-0098-mcp2515-Use-DT-supplied-interrupt-flags.patch36
1 files changed, 36 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-4.19/950-0098-mcp2515-Use-DT-supplied-interrupt-flags.patch b/target/linux/bcm27xx/patches-4.19/950-0098-mcp2515-Use-DT-supplied-interrupt-flags.patch
new file mode 100644
index 0000000000..13f97962f9
--- /dev/null
+++ b/target/linux/bcm27xx/patches-4.19/950-0098-mcp2515-Use-DT-supplied-interrupt-flags.patch
@@ -0,0 +1,36 @@
+From 612a3f0adcf98854dcbe8228551b941b76c6af2c Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+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 <phil@raspberrypi.org>
+---
+ 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
+@@ -948,6 +948,9 @@ 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) {