commit e1191bd4f6 upstream.
A regression is caused by the following commit:
Commit: 02b771b64b
Subject: ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations
In this commit, using system workqueue causes that the maximum parallel
executions of _Qxx can exceed 255. This violates the method reentrancy
limit in ACPICA and generates the following error log:
ACPI Error: Method reached maximum reentrancy limit (255) (20150818/dsmethod-341)
This patch creates a seperate workqueue and limits the number of parallel
_Qxx evaluations down to a configurable value (can be tuned against number
of online CPUs).
Since EC events are handled after driver probe, we can create the workqueue
in acpi_ec_init().
Fixes: 02b771b64b (ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=135691
Reported-and-tested-by: Helen Buus <ubuntu@hbuus.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lv Zheng
6b1f21a111