[PATCH 4.9 080/148] gpio: altera: Use handle_level_irq when configured as a level_high

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Phil Reid <preid@xxxxxxxxxxxxxxxxx>


[ Upstream commit f759921cfbf4847319d197a6ed7c9534d593f8bc ]

When a threaded irq handler is chained attached to one of the gpio
pins when configure for level irq the altera_gpio_irq_leveL_high_handler
does not mask the interrupt while being handled by the chained irq.
This resulting in the threaded irq not getting enough cycles to complete
quickly enough before the irq was disabled as faulty. handle_level_irq
should be used in this situation instead of handle_simple_irq.

In gpiochip_irqchip_add set default handler to handle_bad_irq as
per Documentation/gpio/driver.txt. Then set the correct handler in
the set_type callback.

Signed-off-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpio/gpio-altera.c |   26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

--- a/drivers/gpio/gpio-altera.c
+++ b/drivers/gpio/gpio-altera.c
@@ -90,21 +90,18 @@ static int altera_gpio_irq_set_type(stru
 
 	altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 
-	if (type == IRQ_TYPE_NONE)
+	if (type == IRQ_TYPE_NONE) {
+		irq_set_handler_locked(d, handle_bad_irq);
 		return 0;
-	if (type == IRQ_TYPE_LEVEL_HIGH &&
-		altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH)
-		return 0;
-	if (type == IRQ_TYPE_EDGE_RISING &&
-		altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_RISING)
-		return 0;
-	if (type == IRQ_TYPE_EDGE_FALLING &&
-		altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_FALLING)
-		return 0;
-	if (type == IRQ_TYPE_EDGE_BOTH &&
-		altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_BOTH)
+	}
+	if (type == altera_gc->interrupt_trigger) {
+		if (type == IRQ_TYPE_LEVEL_HIGH)
+			irq_set_handler_locked(d, handle_level_irq);
+		else
+			irq_set_handler_locked(d, handle_simple_irq);
 		return 0;
-
+	}
+	irq_set_handler_locked(d, handle_bad_irq);
 	return -EINVAL;
 }
 
@@ -230,7 +227,6 @@ static void altera_gpio_irq_edge_handler
 	chained_irq_exit(chip, desc);
 }
 
-
 static void altera_gpio_irq_leveL_high_handler(struct irq_desc *desc)
 {
 	struct altera_gpio_chip *altera_gc;
@@ -310,7 +306,7 @@ static int altera_gpio_probe(struct plat
 	altera_gc->interrupt_trigger = reg;
 
 	ret = gpiochip_irqchip_add(&altera_gc->mmchip.gc, &altera_irq_chip, 0,
-		handle_simple_irq, IRQ_TYPE_NONE);
+		handle_bad_irq, IRQ_TYPE_NONE);
 
 	if (ret) {
 		dev_err(&pdev->dev, "could not add irqchip\n");