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Subject[PATCH 2/2] gpio: max732x: Fix irq-events handler
Date
MAX732X doesn't support edge type interrupt. So replace
handle_edge_irq() with handle_level_irq(), which uses
irq_mask/irq_unmask callbacks instead of irq_ack().

This wrong handler may lead to NULL pointer dereference in some cases.
E.g. this was observed on hibernation process:

Unable to handle kernel NULL pointer dereference at virtual address 0
Backtrace:
(handle_edge_irq) from (resend_irqs)
(resend_irqs) from (tasklet_action)
(tasklet_action) from (__do_softirq)
(__do_softirq) from (run_ksoftirqd)
(run_ksoftirqd) from (smpboot_thread_fn)
(smpboot_thread_fn) from (kthread)
(kthread) from (ret_from_fork)

Signed-off-by: Semen Protsenko <semen.protsenko@globallogic.com>
---
drivers/gpio/gpio-max732x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-max732x.c b/drivers/gpio/gpio-max732x.c
index 1885e5c..edade14 100644
--- a/drivers/gpio/gpio-max732x.c
+++ b/drivers/gpio/gpio-max732x.c
@@ -530,7 +530,7 @@ static int max732x_irq_setup(struct max732x_chip *chip,
ret = gpiochip_irqchip_add(&chip->gpio_chip,
&max732x_irq_chip,
irq_base,
- handle_edge_irq,
+ handle_level_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(&client->dev,
--
1.7.9.5


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