]> asedeno.scripts.mit.edu Git - linux.git/commit
PM / devfreq: passive: Use non-devm notifiers
authorLeonard Crestez <leonard.crestez@nxp.com>
Thu, 8 Aug 2019 16:54:08 +0000 (19:54 +0300)
committerMyungJoo Ham <myungjoo.ham@samsung.com>
Sun, 25 Aug 2019 03:47:31 +0000 (12:47 +0900)
commit0ef7c7cce43f6ecc2b96d447e69b2900a9655f7c
treeb0e5cbc3be3ed3947550c50f79e4a9ac34e01325
parent4294a779bd8dff6c65e7e85ffe7a1ea236e92a68
PM / devfreq: passive: Use non-devm notifiers

The devfreq passive governor registers and unregisters devfreq
transition notifiers on DEVFREQ_GOV_START/GOV_STOP using devm wrappers.

If devfreq itself is registered with devm then a warning is triggered on
rmmod from devm_devfreq_unregister_notifier. Call stack looks like this:

devm_devfreq_unregister_notifier+0x30/0x40
devfreq_passive_event_handler+0x4c/0x88
devfreq_remove_device.part.8+0x6c/0x9c
devm_devfreq_dev_release+0x18/0x20
release_nodes+0x1b0/0x220
devres_release_all+0x78/0x84
device_release_driver_internal+0x100/0x1c0
driver_detach+0x4c/0x90
bus_remove_driver+0x7c/0xd0
driver_unregister+0x2c/0x58
platform_driver_unregister+0x10/0x18
imx_devfreq_platdrv_exit+0x14/0xd40 [imx_devfreq]

This happens because devres_release_all will first remove all the nodes
into a separate todo list so the nested devres_release from
devm_devfreq_unregister_notifier won't find anything.

Fix the warning by calling the non-devm APIS for frequency notification.
Using devm wrappers is not actually useful for a governor anyway: it
relies on the devfreq core to correctly match the GOV_START/GOV_STOP
notifications.

Fixes: 996133119f57 ("PM / devfreq: Add new passive governor")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
drivers/devfreq/governor_passive.c