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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-11-23 21:36:51 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-12-01 22:17:32 +0300 |
commit | 4a9af6cac050dce2e895ec3205c4615383ad9112 (patch) | |
tree | 517402e788e888f5fc353bd68cbd4a6febc56a07 /crypto | |
parent | d58071a8a76d779eedab38033ae4c821c30295a5 (diff) | |
download | linux-4a9af6cac050dce2e895ec3205c4615383ad9112.tar.xz |
ACPI: EC: Rework flushing of EC work while suspended to idle
The flushing of pending work in the EC driver uses drain_workqueue()
to flush the event handling work that can requeue itself via
advance_transaction(), but this is problematic, because that
work may also be requeued from the query workqueue.
Namely, if an EC transaction is carried out during the execution of
a query handler, it involves calling advance_transaction() which
may queue up the event handling work again. This causes the kernel
to complain about attempts to add a work item to the EC event
workqueue while it is being drained and worst-case it may cause a
valid event to be skipped.
To avoid this problem, introduce two new counters, events_in_progress
and queries_in_progress, incremented when a work item is queued on
the event workqueue or the query workqueue, respectively, and
decremented at the end of the corresponding work function, and make
acpi_ec_dispatch_gpe() the workqueues in a loop until the both of
these counters are zero (or system wakeup is pending) instead of
calling acpi_ec_flush_work().
At the same time, change __acpi_ec_flush_work() to call
flush_workqueue() instead of drain_workqueue() to flush the event
workqueue.
While at it, use the observation that the work item queued in
acpi_ec_query() cannot be pending at that time, because it is used
only once, to simplify the code in there.
Additionally, clean up a comment in acpi_ec_query() and adjust white
space in acpi_ec_event_processor().
Fixes: f0ac20c3f613 ("ACPI: EC: Fix flushing of pending work")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'crypto')
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