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Rafael J. Wysocki 68bf3b2f95 ACPI: EC: Rework flushing of EC work while suspended to idle
[ Upstream commit 4a9af6cac0 ]

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: f0ac20c3f6 ("ACPI: EC: Fix flushing of pending work")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 11:03:23 +01:00
arch arm64: dts: qcom: msm8916: fix MMC controller aliases 2022-01-27 11:03:22 +01:00
block bfq: Do not let waker requests skip proper accounting 2022-01-27 11:03:18 +01:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: pcrypt - Delay write to padata->info 2021-11-18 19:16:44 +01:00
Documentation Input: i8042 - add deferred probe support 2022-01-05 12:42:32 +01:00
drivers ACPI: EC: Rework flushing of EC work while suspended to idle 2022-01-27 11:03:23 +01:00
fs fs: dlm: fix build with CONFIG_IPV6 disabled 2022-01-27 11:03:13 +01:00
include cgroup: Trace event cgroup id fields should be u64 2022-01-27 11:03:23 +01:00
init init: make unknown command line param message clearer 2021-11-18 19:17:11 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-11-25 09:48:42 +01:00
kernel dma/pool: create dma atomic pool only if dma zone has managed pages 2022-01-27 11:03:00 +01:00
lib siphash: use _unaligned version by default 2021-12-08 09:04:47 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm shmem: fix a race between shmem_unused_huge_shrink and shmem_evict_inode 2022-01-27 11:03:01 +01:00
net netfilter: bridge: add support for pppoe filtering 2022-01-27 11:03:22 +01:00
samples ftrace/samples: Add missing prototypes direct functions 2022-01-11 15:35:13 +01:00
scripts recordmcount.pl: fix typo in s390 mcount regex 2022-01-05 12:42:33 +01:00
security selinux: initialize proto variable in selinux_ip_postroute_compat() 2022-01-05 12:42:34 +01:00
sound ALSA: core: Fix SSID quirk lookup for subvendor=0 2022-01-27 11:02:47 +01:00
tools libbpf: Silence uninitialized warning/error in btf_dump_dump_type_data 2022-01-27 11:03:18 +01:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: downgrade two BUG_ONs to WARN_ON_ONCE 2021-12-22 09:32:34 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm fixes for 5.15 final 2021-10-28 12:17:01 -07:00
Makefile Linux 5.15.16 2022-01-20 09:13:16 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.