Re: [PATCH] i2c: core: Workaround false-positive LOCKDEP in delete_device

Alexander Sverdlin
2022-05-23T07:24:55Z

Hello Wolfram,

On 21/05/2022 11:50, Wolfram Sang wrote:
>> + /*
>> + * We drop the mutex here, because device unregister
>> + * will take sysfs lock (kn->count) which, as LOCKDEP
>> + * would think, depends on this mutex
>> + */
> I have to ask: can't lockdep be fixed or the lock somehow be annotated
> to prevent the false positive?

I would be happy to test any other proposal, I personally didn't find other working
approach until now. This particular patch actually has an advantage of reducing the
locked region, which makes sense if only userspace_clients is protected by the mutex.

--
Best regards,
Alexander Sverdlin.