Re: [PATCH 3/9] gpio: mxc: cache compatible checks at probe time

[Andy Shevchenko]

On Sat, Oct 3, 2026 at 3:09 PM Peng Fan (OSS) <peng.fan@xxxxxxxxxxx> wrote:

> mxc_gpio_generic_config() and mxc_gpio_set_pad_wakeup() call
> of_device_is_compatible() on every invocation to determine pad wakeup
> capability and i.MX8QM-specific behavior. These properties are
> invariant for the lifetime of the device.
>
> Cache them as bool fields (has_pad_wakeup, is_imx8qm) in mxc_gpio_port
> during probe, eliminating repeated device tree string comparisons in
> the suspend/resume hot path.

...

>  {
> -       struct device_node *np = port->dev->of_node;
> -
> -       if (of_device_is_compatible(np, "fsl,imx8dxl-gpio") ||
> -           of_device_is_compatible(np, "fsl,imx8qxp-gpio") ||
> -           of_device_is_compatible(np, "fsl,imx8qm-gpio"))
> -               return (gpiochip_generic_config(&port->gen_gc.gc,
> -                                               offset, conf) == 0);
> +       if (!port->has_pad_wakeup)
> +               return false;
>
> -       return false;
> +       return (gpiochip_generic_config(&port->gen_gc.gc, offset, conf) == 0);

Too many parentheses, also the semantic of 0 is not obvious. Better,
for example, this one

  int ret;
  ...
  ret = gpiochip_generic_config(...);
  if (ret)
    return false;

  return true;

>  }

-- 
With Best Regards,
Andy Shevchenko