On Wed, Nov 14, 2018 at 11:48 AM Chanwoo Choi <cw00.choi@xxxxxxxxxxx> wrote: > > On 2018년 11월 14일 18:36, Andy Shevchenko wrote: > > On Wed, Nov 14, 2018 at 06:13:37PM +0900, Chanwoo Choi wrote: > >> On 2018년 11월 14일 17:35, Andy Shevchenko wrote: > >>> On Wed, Nov 14, 2018 at 1:53 AM Chanwoo Choi <cw00.choi@xxxxxxxxxxx> wrote: > >>> > >>>> I was thinking about again to change from NULL to EPROBE_DEFER. > >>>> > >>>> extcon_get_extcon_dev() function was almost called in the probe function. > >>>> But, this function might be called on other position instead of probe. > >>> > >>> *Might be* sounds like a theoretical thing, care to share what is in you mind? > >>> Current users and more important the new coming one are *all* doing the same. > >>> > >>>> ENODEV is more correct error instead of EPROBE_DEFER. > >>> > >>> So, you are proposing to continue duplicating conversion from ENODEV > >>> to EPROBE_DEFER in *each* caller? > >> > >> The extcon core don't know the caller situation is in either probe() or other position > >> in the caller driver. The caller driver should decide the kind of error value > >> by using the return value of extcon_get_extcon_dev(). > >> > >> extcon_get_extcon_dev() function cannot be modified for only one case. > >> If some device driver call extcon_get_extcon_dev() out of probe() fuction, > >> EPROBE_DEFER is not always correct. > > > > I agree with this, but look at the current state of affairs. All users do the same. > > If we need to have another case we may consider this later. > > Because we know the potential wrong case of this change, I can't agree this change. > If extcon_get_extcon_dev() returns ENODEV instead of EPROBE_DEFER, > it is clear and then there are no problem on both current and future. Changing NULL to -ENODEV is a trading bad to worse. I would not go that way, so, it's your call. > > API inside the kernel are not carved in the stone. Only can repeat myself (see above). While I see *theoretical* rationale on your side, mine has *practical* proofs. So, I'm giving up on this and will duplicate same what it's done in 4 current callers. -- With Best Regards, Andy Shevchenko
