Re: [PATCH v2 17/23] gpio: reduce the functionality of validate_desc()

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Mon, Feb 05, 2024 at 10:34:12AM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> 
> Checking desc->gdev->chip for NULL without holding it in place with some
> serializing mechanism is pointless. Remove this check. Also don't check
> desc->gdev for NULL as it can never happen. We'll be protecting
> gdev->chip with SRCU soon but we will provide a dedicated, automatic
> class for that.

...

>  void gpiod_free(struct gpio_desc *desc)
>  {
> -	/*
> -	 * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip
> -	 * may already be NULL but we still want to put the references.
> -	 */
> -	if (!desc)
> -		return;
> +	VALIDATE_DESC_VOID(desc);

IIRC we (used to) have two cases like this (you added one in some code like
last year).

-- 
With Best Regards,
Andy Shevchenko