Am Thu, 25 Aug 2022 21:03:53 +0300 schrieb Andy Shevchenko <andy.shevchenko@xxxxxxxxx>: > On Thu, Aug 25, 2022 at 8:51 PM Henning Schild > <henning.schild@xxxxxxxxxxx> wrote: > > Am Thu, 25 Aug 2022 12:44:20 +0200 > > schrieb Henning Schild <henning.schild@xxxxxxxxxxx>: > > ... > > > Concerning these two tables from above i have a question i need to > > find an answer for for maintaining the out-of-tree modules of these > > drivers. > > > > When getting the drivers into the kernel i had to rename the leds > > but in out-of-tree i would like to keep the old names and just > > equip their setters/getters with a deprecation warning. Just to > > give existing users time to slowly adopt the upstream name change > > if i can. > > > > In the open-coded way i just defined each LED twice and added a > > strcmp > > + pr_warn. With the "leds-gpio" version i still fail to find a > > solution which does not get me into -EBUSY. So i already fail at > > the second definition of the legacy name, not even had a chance to > > think about how to smuggle in my deprecation warning. > > > > I know out-of-tree is not a concern to people here, but someone > > might have an answer anyhow. > > Yes, we (upstream) don't care about out-of-tree stuff. But I think > what you are asking for is kinda an alias. Maybe you simply can create > a module that will wait for the led appearing (by notify that adds a > device or alike) and create an alias by sysfs symlink (IIRC there are > kernel APIs for that)? It will be another out-of-tree module that you > may drop whenever is time. Thanks! That sounds like a very good idea indeed. Would also keep the code free of #ifdef and reduce the maint effort for the out-of-tree. I was trying udev earlier but failed. Will give such a symlink driver a try. Might be hard to get the deprecation warning into each access, but will have to resort to probe-time instead of access-time. regards, Henning
