Messages in this thread | | | Date | Wed, 22 Dec 2021 10:16:20 +0100 | Subject | Re: [PATCH] nvmem: fix unregistering device in nvmem_register() error path | From | Rafał Miłecki <> |
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On 22.12.2021 10:08, Johan Hovold wrote: > On Wed, Dec 22, 2021 at 10:00:03AM +0100, Rafał Miłecki wrote: >> On 22.12.2021 09:38, Johan Hovold wrote: > >>> It seems Rafał is mistaken here too; you certainly need to call >>> platform_device_put() if platform_device_register() fail, even if many >>> current users do appear to get this wrong. >> >> Yes I was! Gosh I made up that "platform_device_put()" name and only >> now I realized it actually exists! >> >> I stand by saying this design is really misleading. Even though >> platform_device_put() was obviously a bad example. >> >> Please remember I'm just a minor kernel developer however in my humble >> opinion behaviour of device_register() and platform_device_register() >> should be changed. >> >> If any function fails I expect: >> 1. That function to clean up its mess if any >> 2. Me to be responsible to clean up my mess if any >> >> This is how "most" code (whatever it means) works. >> 1. If POSIX snprintf() fails I'm not expected to call *printf_put() sth >> 2. If POSIX bind() fails I'm not expected to call bind_put() sth >> 3. (...) >> >> I'm not sure if those are the best examples but you should get my point. > > Yes, and we all agree that it's not the best interface. But it exists, > and changing it now risks introducing worse problem than a minor, mostly > theoretical, memleak.
Thanks for confirming that, I was wondering if it's just my mind that doesn't find this design clear enough.
Now, assuming this design isn't perfect and some purists would like it cleaned up:
Would that make sense to introduce something like 1. device_register2() / device_add2() and 2. platform_device_register2() / platform_device_add2()
that would *not* require calling *_put() on failure? Then start converting existing drivers to those new (clearner?) helpers?
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