lkpi_i2c_del_adapter can't delete child when i2c_adapter remove

[shichun_ma_dell.com]

Summary

with intel drm driver attach, then it can support monitor dynamic plug in/out. it will call i2c_add_adapter when attach monitor, and i2c_del_adapter when detach monitor.
previous code can't delete i2c device successfully. and i2c device should be deleted in each *_detach function.

[shichun_ma_dell.com]

Any one can have a review with this diff?

[bz]

The remainder I'll leave to @manu and @wulf . I don't know enough of the implications.

sys/compat/linuxkpi/common/include/linux/device.h

517

Are you sure this is correct and doesn't lead to a leak in the destroy case?
Also seems unrelated to this problem.

sys/compat/linuxkpi/common/src/linux_i2c.c

27

That's likely not needed anymore. See fdafd315ad0d0f28a11b9fb4476a9ab059c62b92

[shichun_ma_dell.com]

sys/compat/linuxkpi/common/include/linux/device.h

517

devt is initialized by makdev(0, device_get_unit(dev->bsddev)); it's not resource that malloced.
so I think it's safe to set zero.

[wulf]

sys/compat/linuxkpi/common/src/linux_i2c.c

61

Can we avoid double creation of device children for every I2C instance? One through LKPI and than one with FreeBSD KPI?