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authorLv Zheng <lv.zheng@intel.com>2017-04-04 19:32:17 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-04-12 12:41:18 +0200
commitc1e94148f93c4319a1aea4ae29835cd1e2017ff9 (patch)
treecd59abdd479e707ca6683ab4c017748cfa951d8f /Documentation/kernel-parameters.txt
parent43cfff65c989c0ef722bfcd2335b07a48e09aab9 (diff)
downloadlinux-aarch64-c1e94148f93c4319a1aea4ae29835cd1e2017ff9.tar.gz
ACPI / sysfs: Provide quirk mechanism to prevent GPE flooding
[ Upstream commit 9c4aa1eecb48cfac18ed5e3aca9d9ae58fbafc11 ] Sometimes, the users may require a quirk to be provided from ACPI subsystem core to prevent a GPE from flooding. Normally, if a GPE cannot be dispatched, ACPICA core automatically prevents the GPE from firing. But there are cases the GPE is dispatched by _Lxx/_Exx provided via AML table, and OSPM is lacking of the knowledge to get _Lxx/_Exx correctly executed to handle the GPE, thus the GPE flooding may still occur. The existing quirk mechanism can be enabled/disabled using the following commands to prevent such kind of GPE flooding during runtime: # echo mask > /sys/firmware/acpi/interrupts/gpe00 # echo unmask > /sys/firmware/acpi/interrupts/gpe00 To avoid GPE flooding during boot, we need a boot stage mechanism. This patch provides such a boot stage quirk mechanism to stop this kind of GPE flooding. This patch doesn't fix any feature gap but since the new feature gaps could be found in the future endlessly, and can disappear if the feature gaps are filled, providing a boot parameter rather than a DMI table should suffice. Link: https://bugzilla.kernel.org/show_bug.cgi?id=53071 Link: https://bugzilla.kernel.org/show_bug.cgi?id=117481 Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/887793 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt10
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 65b05ba6ef98..a6fadef92d6d 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -305,6 +305,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
use by PCI
Format: <irq>,<irq>...
+ acpi_mask_gpe= [HW,ACPI]
+ Due to the existence of _Lxx/_Exx, some GPEs triggered
+ by unsupported hardware/firmware features can result in
+ GPE floodings that cannot be automatically disabled by
+ the GPE dispatcher.
+ This facility can be used to prevent such uncontrolled
+ GPE floodings.
+ Format: <int>
+ Support masking of GPEs numbered from 0x00 to 0x7f.
+
acpi_no_auto_serialize [HW,ACPI]
Disable auto-serialization of AML methods
AML control methods that contain the opcodes to create