Quoting rojay@xxxxxxxxxxxxxx (2021-05-07 03:07:42) > On 2021-05-05 07:08, Stephen Boyd wrote: > > Quoting Roja Rani Yarubandi (2021-04-20 04:13:55) > > > In fact, where is that code? I'd expect to see i2c_del_adapter() in > > here > > so we know the adapter can't accept transfers anymore. Maybe > > i2c_del_adapter() could be called, and then there's nothing to do after > > that? This whole patch is trying to rip the adapter out from under the > > i2c core framework, when we should take the opposite approach and > > remove > > it from the core framework so that it can't transfer anything anymore > > and thus the IOMMU can remove the mapping. > > > > IIUC about probe/remove/shutdown calls, during "remove" we will unplug > the > device with opposite calls to "probe's" plug operations. > For example i2c_add_adapter() from 'probe' and i2c_del_adapter() from > 'remove'. > For "shutdown", as system is going to shutdown, there is no need of > unplug > operations to be done. > > And also, I had a glance on other upstream i2c drivers, and noticed > "i2c-i801.c" > driver has i2c_del_adapter() called from remove callback but not from > shutdown > callback. Sure, other drivers could also be broken. > > And actually I tried calling i2c_del_adapter() from geni_i2c_shutdown(), > and it resulted in below WARNING trace > [ 90.320282] Call trace: > [ 90.322807] _regulator_put+0xc4/0xcc > [ 90.326583] regulator_bulk_free+0x48/0x6c > [ 90.330808] devm_regulator_bulk_release+0x20/0x2c > [ 90.335744] release_nodes+0x1d0/0x244 > [ 90.339609] devres_release_all+0x3c/0x54 > [ 90.343735] device_release_driver_internal+0x108/0x194 > [ 90.349109] device_release_driver+0x24/0x30 > [ 90.353510] bus_remove_device+0xd0/0xf4 > [ 90.357548] device_del+0x1a8/0x2f8 > [ 90.361143] device_unregister+0x1c/0x34 > [ 90.365181] __unregister_client+0x78/0x88 > [ 90.369397] device_for_each_child+0x64/0xb4 > [ 90.373797] i2c_del_adapter+0xf0/0x1d4 > [ 90.377745] geni_i2c_shutdown+0x9c/0xc0 > [ 90.381783] platform_drv_shutdown+0x28/0x34 > [ 90.386182] device_shutdown+0x148/0x1f0 > > Can you please suggest me what might be missing here? > It looks like some device that is on the i2c bus is putting a regulator in the remove path without disabling it. Can you print out which device driver it is and fix that driver to call regulator_disable() on the driver remove path? I'll try locally and see if I can find the driver too.
