On Wed, May 7, 2025 at 1:10 PM Thomas Richard <[email protected]> wrote: > On 5/7/25 08:34, Andy Shevchenko wrote: > > On Tue, May 6, 2025 at 6:21 PM Thomas Richard > > <[email protected]> wrote:
... > >> + /* > >> + * get_direction() is called during gpiochip registration, return > >> input > >> + * direction if there is no descriptor for the line. > >> + */ > >> + if (!test_bit(offset, fwd->valid_mask)) > >> + return GPIO_LINE_DIRECTION_IN; > > > > Can you remind me why we choose a valid return for invalid line? From > > a pure code perspective this should return an error. > > I reproduced gpiolib behavior. During gpiochip registration, we get the > direction of all lines. In the case the line is not valid, it is marked > as input if direction_input operation exists, otherwise it is marked as > output. [1] > > But in fact we could return an error and the core will mark the line as > input. Maybe ENODEV ? I am fine with this error code, but do we have similar cases already in the kernel? Do they use the same or different error code(s)? > [1] > https://elixir.bootlin.com/linux/v6.15-rc5/source/drivers/gpio/gpiolib.c#L1105-L1123 -- With Best Regards, Andy Shevchenko
