[PATCH v6 02/13] gpio: mxc: fix both_edges bit operations

[Andy Shevchenko]

On Sun, Oct 11, 2026 at 2:54 PM Peng Fan (OSS) <peng.fan at oss.nxp.com> wrote:
>
> gpio_set_irq_type() can be called concurrently for different pins on
> the same port.  The IRQ core serializes per irq descriptor, but
> different pins have different descriptors, so on SMP systems two
> concurrent gpio_set_irq_type() calls for pins on the same port run
> without mutual exclusion.
>
> The read-modify-write of port->both_edges is performed outside the
> port-wide scoped_guard(gpio_generic_lock_irqsave) section, so
> concurrent updates for different pins can overwrite each other,
> causing missed interrupts or stuck IRQ lines on dual-edge triggered
> pins.
>
> The original uniprocessor MXC SoCs were not affected; the race
> became reachable on multi-core i.MX7 and i.MX8 SoCs that reuse this
> driver.
>
> Convert both_edges from u32 to unsigned long and use set_bit(),
> clear_bit(), and test_bit() to make the modifications atomic.

Is bitops.h already included?

-- 
With Best Regards,
Andy Shevchenko