linux-kernel - Re: [PATCH] gpiolib: acpi: Add ACPI device NULL check to acpi_can_fallback_to

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Date: Fri, 10 May 2024 17:46:13 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Laura Nao <laura.nao@...labora.com>
Cc: mika.westerberg@...ux.intel.com, linus.walleij@...aro.org,
	brgl@...ev.pl, kernel@...labora.com, linux-kernel@...r.kernel.org,
	linux-gpio@...r.kernel.org, linux-acpi@...r.kernel.org,
	"kernelci.org bot" <bot@...nelci.org>
Subject: Re: [PATCH] gpiolib: acpi: Add ACPI device NULL check to
 acpi_can_fallback_to_crs()

On Thu, May 09, 2024 at 12:46:05PM +0200, Laura Nao wrote:
> Check ACPI device for NULL inside acpi_can_fallback_to_crs(), so callers
> won't need to.

Thank you for the patch, one change seems good to have along this.

..

>  	/* Never allow fallback if the device has properties */
> -	if (acpi_dev_has_props(adev) || adev->driver_gpios)
> +	if (!adev || acpi_dev_has_props(adev) || adev->driver_gpios)

Right, since it was adev || _crs() combined.

>  		return false;

Now we may remove that check from __acpi_find_gpio():

--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -988,10 +988,10 @@ __acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id, unsigned int
 	}
 
 	/* Then from plain _CRS GPIOs */
-	if (!adev || !can_fallback)
-		return ERR_PTR(-ENOENT);
+	if (can_fallback)
+		return acpi_get_gpiod_by_index(adev, NULL, idx, info);
 
-	return acpi_get_gpiod_by_index(adev, NULL, idx, info);
+	return ERR_PTR(-ENOENT);
 }
 
 struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,


As a side effect it will make the comment better to understand.

With above suggestion applied, feel free to add mine
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

You might need to rephrase the commit message to say that

 "We also move the check in additional to the moving the function call
 outside of __acpi_find_gpio()."

or something similar, up to you.

-- 
With Best Regards,
Andy Shevchenko