On 1/13/22 12:45 AM, Mark Brown wrote: [...] > (Do we really need *all* the CCs here?) Yeah, 25 files were changed and that resulted in 75 persons/lists addressed. I didn't expect such a wide audience myself... :-) >> That convinces me, that platform_get_irq_optional() is a bad name. The >> only difference to platform_get_irq is that it's silent. And returning >> a dummy irq value (which would make it aligned with the other _optional >> functions) isn't possible. > There is regulator_get_optional() which is I believe the earliest of > these APIs, it doesn't return a dummy either (and is silent too) - this Hm, I'm seeing it's rather noisy... :-) > is because regulator_get() does return a dummy since it's the vastly > common case that regulators must be physically present and them not > being found is due to there being an error in the system description. > It's unfortunate that we've ended up with these two different senses for > _optional(), people frequently get tripped up by it. > >>> To me it sounds much more logical for the driver to check if an >>> optional irq is non-zero (available) or zero (not available), than to >>> sprinkle around checks for -ENXIO. In addition, you have to remember >>> that this one returns -ENXIO, while other APIs use -ENOENT or -ENOSYS >>> (or some other error code) to indicate absence. I thought not having >>> to care about the actual error code was the main reason behind the >>> introduction of the *_optional() APIs. > >> No, the main benefit of gpiod_get_optional() (and clk_get_optional()) is >> that you can handle an absent GPIO (or clk) as if it were available. Hm, I've just looked at these and must note that they match 1:1 with platform_get_irq_optional(). Unfortunately, we can't however behave the same way in request_irq() -- because it has to support IRQ0 for the sake of i8253 drivers in arch/... > Similarly for the regulator API, kind of. MBR, Sergey
