On Fri, Jul 31, 2020 at 2:39 PM Ahmad Fatoum [off-list ref] wrote:

Commit 959bc7b22bd2 ("gpio: Automatically add lockdep keys") documents
in its commits message its intention to "create a unique class key for
each driver".

It does so by having gpiochip_add_data add in-place the definition of
two static lockdep classes for LOCKDEP use. That way, every caller of
the macro adds their gpiochip with unique lockdep classes.

There are many indirect callers of gpiochip_add_data, however, via
use of devm_gpiochip_add_data. devm_gpiochip_add_data has external
linkage and all its users will share the same lockdep classes, which
probably is not intended.

Fix this by replicating the gpio_chip_add_data statics-in-macro for
the devm_ version as well.

Fixes: 959bc7b22bd2 ("gpio: Automatically add lockdep keys")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
This doesn't fix any particular problem I ran into, but the code
looked buggy, at least to my lockdep-user-not-developer eyes.

Thanks patch applied, I think we had this fixed before
but managed to loose it in some API rewrite. Thanks for
fixing it up!

Yours,
Linus Walleij