Re: [PATCH v2] gpio: max732x: Fix irq-events handler

From: Grygorii Strashko
Date: Fri Apr 24 2015 - 06:29:48 EST

On 04/22/2015 04:20 PM, Semen Protsenko wrote:
MAX732X clears all pending interrupts on I2C read (when interrupts
register is being read). Driver doesn't need to send any ACKs when
interrupt was handled. So replace handle_edge_irq() with

Using handle_edge_irq() (w/o .irq_ack callback set) 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
(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@xxxxxxxxxxxxxxx>

Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxxxxxx>

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..86dc6b3 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,
- handle_edge_irq,
+ handle_simple_irq,
if (ret) {

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