On 28/02/2025 11:42, Matti Vaittinen wrote:
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()
Would something like this be appropriate? It seems to work "on my
machine" :) Do you see any unwanted side-effects?
+++ b/drivers/gpio/gpiolib.c
@@ -2315,6 +2315,10 @@ static int gpiod_request_commit(struct gpio_desc
*desc, const char *label)
if (!guard.gc)
return -ENODEV;
+ offset = gpio_chip_hwgpio(desc);
+ if (!gpiochip_line_is_valid(guard.gc, offset))
+ return -EINVAL;
+
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
return -EBUSY;
@@ -2323,11 +2327,7 @@ static int gpiod_request_commit(struct gpio_desc
*desc, const char *label)
*/
if (guard.gc->request) {
- offset = gpio_chip_hwgpio(desc);
- if (gpiochip_line_is_valid(guard.gc, offset))
- ret = guard.gc->request(guard.gc, offset);
- else
- ret = -EINVAL;
+ ret = guard.gc->request(guard.gc, offset);
if (ret)
goto out_clear_bit;
}
I can craft a formal patch if this seems reasonable.
Yours,
-- Matti
