On Sat, Dec 4, 2021 at 6:04 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Fri, Nov 26, 2021 at 11:38 AM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \ > > acpi-5.16-rc3 > > Hmm. This may be unrelated, but I don't think I've seen this before.. No, this is not related. It shows up because of the drain_workqueue() in __acpi_ec_flush_work(). > On my laptop, I get > > WARNING: CPU: 4 PID: 95940 at kernel/workqueue.c:1441 __queue_work+0x2f9/0x3b0 > Workqueue: kec_query acpi_ec_event_processor > .. > Call Trace: > <TASK> > queue_work_on+0x20/0x30 So this tries to add work to ec_wq while it is draining AFAICS. > advance_transaction+0x1a1/0x500 > acpi_ec_transaction+0x15c/0x410 > acpi_ec_space_handler+0xd2/0x270 > acpi_ev_address_space_dispatch+0x216/0x2a3 > ? acpi_ec_resume+0x20/0x20 > acpi_ex_access_region+0x1dc/0x255 > ? acpi_os_wait_semaphore+0x48/0x70 > acpi_ex_field_datum_io+0xfd/0x178 > acpi_ex_read_data_from_field+0x12e/0x171 > acpi_ex_resolve_node_to_value+0x1fe/0x281 > acpi_ds_evaluate_name_path+0x75/0xe9 > acpi_ds_exec_end_op+0x8f/0x411 > acpi_ps_parse_loop+0x495/0x5bc > acpi_ps_parse_aml+0x94/0x2c2 > acpi_ps_execute_method+0x15e/0x193 > acpi_ns_evaluate+0x1c6/0x25d > acpi_evaluate_object+0x12e/0x226 > acpi_ec_event_processor+0x63/0x90 > process_one_work+0x217/0x3c0 > > and it seems to be happening at resume time. > > This was when running a51e3ac43ddb, so not the very latest git tree, > but recent. > > Maybe I've missed a report of this? It's not been reported or at least I can't recall that, but it is not a new issue. There is a commit to address this in my linux-next branch: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=linux-next&id=4a9af6cac050dce2e895ec3205c4615383ad9112 but it is interesting that you can reproduce it. I thought it would be rather theoretical.
