[PATCH v2] gpio/gpiolib: Forbid irqchip default trigger if probed over DT

From: Marc Zyngier
Date: Wed Sep 07 2016 - 04:12:25 EST


Using a default trigger is a bad idea if using DT to configure
interrupts, as the device's interrupt specifier will always contain
the trigger configuration.

Let's warn about that particular situation, and revert to not
having a default. Hopefully, the couple of drivers still using
this feature will quickly be fixed.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
Send the tested patch this time around...

drivers/gpio/gpiolib.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 53ff25a..5707b5d 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1617,6 +1617,15 @@ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
if (gpiochip->of_node)
of_node = gpiochip->of_node;
#endif
+ /*
+ * Specifying a default trigger is a terrible idea if DT is
+ * used to configure the interrupts, as you may end-up with
+ * conflicting triggers. Tell the user, and reset to NONE.
+ */
+ if (WARN(of_node && type != IRQ_TYPE_NONE,
+ "%s: Ignoring %d default trigger\n", of_node->full_name, type))
+ type = IRQ_TYPE_NONE;
+
gpiochip->irqchip = irqchip;
gpiochip->irq_handler = handler;
gpiochip->irq_default_type = type;
--
2.1.4