Re: [PATCH] gpio: Document the 'valid_mask' being internal

From: Matti Vaittinen
Date: Fri Feb 28 2025 - 04:43:02 EST


On 28/02/2025 11:28, Matti Vaittinen wrote:

CC: Geert (because, I think he was asked about the Rcar GPIO check before).

On 28/02/2025 10:23, Linus Walleij wrote:
On Thu, Feb 27, 2025 at 9:24 AM Matti Vaittinen
<mazziesaccount@xxxxxxxxx> wrote:

The call graph should look like this:

devm_gpiod_get_array()
     gpiod_get_array()
         gpiod_get_index(0...n)
             gpiod_find_and_request()
                 gpiod_request()
                     gpiod_request_commit()

Here in my setup the guard.gc->request == NULL. Thus the code never goes to the branch with the validation. And just before you ask me why the guard.gc->request is NULL - what do you call a blind bambi? :)
 - No idea.

Oh, I suppose the 'guard.gc' is just the chip structure. So, these validity checks are only applied if the gc provides the request callback? As far as I understand, the request callback is optional, and thus the validity check for GPIOs may be omitted.


                         gpiochip_line_is_valid()

Eg, This is never called.


Yours,
-- Matti