2016-09-18 10:52 GMT+02:00 Peter Rosin [off-list ref]:

On 2016-09-16 19:58, Wolfram Sang wrote:

quoted

Same here. And if it prevents us from false positive lockdep reports, I
am all for fixing it.

Except it doesn't, when I think some more about it...

If you have two gpio-expanders on the same depth but on different i2c
branches you still end up with a splat if one is used to control a mux
to reach the other.

The only way to solve it for good, that I see, is to have every instance
of the gpio-expander mutex in its own class. That might lead to many
lockdep classes but then again, how many gpio expanders could there be
in a system? A dozen or two seems extreme, so maybe that is the correct
approach anyway?

Wouldn't it be enough to have a separate class for every base (as in:
not having any parent adapters) i2c adapter?

Best regards,
Bartosz Golaszewski