On Mon, Feb 6, 2017 at 8:46 AM, João Paulo Rechi Vita <jprvita@xxxxxxxxx> wrote: > Yes, the real problem is i2c_hid not being probed for the touchpad > device on this platform The lack of probe was because when i2c_acpi_add_device() called acpi_bus_get_device() on the handle for the touchpad device (TPL1), it was returning the acpi_device for something totally unrelated. We checked that the original handle-to-device mapping was set up correctly before that point, hence this looks like memory corruption, and the problem went away as soon as we fixed the double free. > [ 0.317002] ACPI Warning: Obj ffffa00472a445e8, Reference Count is > already zero, cannot decrement > [ 0.317178] (20160422/utdelete-442) > >> See this bug for reference: >> https://bugs.acpica.org/show_bug.cgi?id=1336 >> > > Looks like it could be the same problem, indeed. I'm attaching a > kernel log with acpi.trace_debug_layer=0x10091 > acpi.trace_debug_level=0x107FFF > acpi.trace_method_name=_SB.PCI0.I2C1.TPL1._CID > acpi.trace_state=opcode, which is what I was using to investigate the > problem The debug messages in that log stop when the method execution completes, so it may also be useful to share a part of an earlier log where you can see the double freeing happen in a bit more detail. For each of the 2 objects double-freed below we confirmed that the first unreference is the one in acpi_ns_repair_HID and the second unreference is the one removed in JP's patch. nsprepkg-0105 ns_check_package : \_SB.PCI0.I2C1.TPL1._CID Validating return Package of Type 2, Count 2 utobject-0404 ut_allocate_object_des: ffff940f6ba36480 Size 48 utdelete-0750 ut_remove_reference : Obj ffff940f6ba36cf0 Current Refs=1 [To Be Decremented] utdelete-0447 ut_update_ref_count : Obj ffff940f6ba36cf0 Type 02 Refs 00 [Decremented] utdelete-0096 ut_delete_internal_obj: **** String ffff940f6ba36cf0, ptr ffff9f654004e2a8 utdelete-0336 ut_delete_internal_obj: Deleting Object ffff940f6ba36cf0 [String] utdelete-0750 ut_remove_reference : Obj ffff940f6ba36cf0 Current Refs=0 [To Be Decremented] ACPI Warning: Obj ffff940f6ba36cf0, Reference Count is already zero, cannot decrement (20160422/utdelete-442) utdelete-0447 ut_update_ref_count : Obj ffff940f6ba36cf0 Type 02 Refs 00 [Decremented] utdelete-0096 ut_delete_internal_obj: **** String ffff940f6ba36cf0, ptr ffff9f654004e2a8 utdelete-0336 ut_delete_internal_obj: Deleting Object ffff940f6ba36cf0 [String] utobject-0404 ut_allocate_object_des: ffff940f6ba36cf0 Size 48 utdelete-0750 ut_remove_reference : Obj ffff940f6ba36c60 Current Refs=1 [To Be Decremented] utdelete-0447 ut_update_ref_count : Obj ffff940f6ba36c60 Type 02 Refs 00 [Decremented] utdelete-0096 ut_delete_internal_obj: **** String ffff940f6ba36c60, ptr ffff9f654004e2b2 utdelete-0336 ut_delete_internal_obj: Deleting Object ffff940f6ba36c60 [String] utdelete-0750 ut_remove_reference : Obj ffff940f6ba36c60 Current Refs=0 [To Be Decremented] ACPI Warning: Obj ffff940f6ba36c60, Reference Count is already zero, cannot decrement (20160422/utdelete-442) utdelete-0447 ut_update_ref_count : Obj ffff940f6ba36c60 Type 02 Refs 00 [Decremented] utdelete-0096 ut_delete_internal_obj: **** String ffff940f6ba36c60, ptr ffff9f654004e2b2 utdelete-0336 ut_delete_internal_obj: Deleting Object ffff940f6ba36c60 [String] nseval-0315 ns_evaluate : *** Completed evaluation of object _CID *** Thanks, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
