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

From: Linus Walleij
Date: Wed May 06 2015 - 09:09:50 EST


On Wed, Apr 22, 2015 at 3:20 PM, Semen Protsenko
<semen.protsenko@xxxxxxxxxxxxxxx> 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
> handle_simple_irq().
>
> 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
> 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@xxxxxxxxxxxxxxx>

Patch applied with Grygorii's Review tag.

Yours,
Linus Walleij
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