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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 05:35:13 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 05:35:13 +0300 |
commit | 59df1c2bdecb0d1aaadfb8533df4bea528ee4952 (patch) | |
tree | ded1e05c84622331dd6a61b24db31e9b920f6970 /Documentation/acpi/method-customizing.txt | |
parent | c620f7bd0ba5c882b3e7fc199a8d5c2f6c2f5263 (diff) | |
parent | 10b4768b27a0b8f9459570723ecb1809f4d707e0 (diff) | |
download | linux-59df1c2bdecb0d1aaadfb8533df4bea528ee4952.tar.xz |
Merge tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI updates from Rafael Wysocki:
"These rearrange the ACPI documentation by converting it to the .rst
format and splitting it into clear categories (admin guide, driver
API, firmware guide), switch over multiple users of a problematic
library function to a new better one, update the ACPICA code in the
kernel to a new upstream release, fix a few issues, improve power
device management diagnostics and do some cleanups.
Specifics:
- Convert the ACPI documentation in the kernel source tree to the
.rst format and split it into the admin guide, driver API and
firmware guide parts (Changbin Du).
- Add a PRP0001 usage example to the ACPI documentation (Thomas
Preston).
- Switch over the users of the acpi_dev_get_first_match_name()
library function which turned out to be problematic to a new,
better one called acpi_dev_get_first_match_dev() (Andy Shevchenko,
YueHaibing).
- Update the ACPICA code in the kernel to upstream release 20190405
including:
* Null pointer dereference check in acpi_ns_delete_node() (Erik
Schmauss).
* Multiple macro and function name changes (Bob Moore).
* Predefined operation region name fix (Erik Schmauss).
- Fix hibernation issue on systems using the Baytrail and Cherrytrail
Intel SoCs introduced during the 4.20 development cycle (Hans de
Goede).
- Add Sony VPCEH3U1E to the backlight quirk list (Zhang Rui).
- Fix button handling during system resume (Zhang Rui).
- Add a device PM diagnostic message (Rafael Wysocki).
- Clean up the code, comments and white space in multiple places
(Bjorn Helgaas, Gustavo Silva, Kefeng Wang)"
* tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
Documentation: ACPI: move video_extension.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move apei/einj.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move apei/output_format.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST
Documentation: ACPI: move debug.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsd/data-node-references.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsd/graph.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move acpi-lid.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsdt-override.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move method-customizing.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert to reST
Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST
Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi and convert to reST
...
Diffstat (limited to 'Documentation/acpi/method-customizing.txt')
-rw-r--r-- | Documentation/acpi/method-customizing.txt | 73 |
1 files changed, 0 insertions, 73 deletions
diff --git a/Documentation/acpi/method-customizing.txt b/Documentation/acpi/method-customizing.txt deleted file mode 100644 index 7235da975f23..000000000000 --- a/Documentation/acpi/method-customizing.txt +++ /dev/null @@ -1,73 +0,0 @@ -Linux ACPI Custom Control Method How To -======================================= - -Written by Zhang Rui <rui.zhang@intel.com> - - -Linux supports customizing ACPI control methods at runtime. - -Users can use this to -1. override an existing method which may not work correctly, - or just for debugging purposes. -2. insert a completely new method in order to create a missing - method such as _OFF, _ON, _STA, _INI, etc. -For these cases, it is far simpler to dynamically install a single -control method rather than override the entire DSDT, because kernel -rebuild/reboot is not needed and test result can be got in minutes. - -Note: Only ACPI METHOD can be overridden, any other object types like - "Device", "OperationRegion", are not recognized. Methods - declared inside scope operators are also not supported. -Note: The same ACPI control method can be overridden for many times, - and it's always the latest one that used by Linux/kernel. -Note: To get the ACPI debug object output (Store (AAAA, Debug)), - please run "echo 1 > /sys/module/acpi/parameters/aml_debug_output". - -1. override an existing method - a) get the ACPI table via ACPI sysfs I/F. e.g. to get the DSDT, - just run "cat /sys/firmware/acpi/tables/DSDT > /tmp/dsdt.dat" - b) disassemble the table by running "iasl -d dsdt.dat". - c) rewrite the ASL code of the method and save it in a new file, - d) package the new file (psr.asl) to an ACPI table format. - Here is an example of a customized \_SB._AC._PSR method, - - DefinitionBlock ("", "SSDT", 1, "", "", 0x20080715) - { - Method (\_SB_.AC._PSR, 0, NotSerialized) - { - Store ("In AC _PSR", Debug) - Return (ACON) - } - } - Note that the full pathname of the method in ACPI namespace - should be used. - e) assemble the file to generate the AML code of the method. - e.g. "iasl -vw 6084 psr.asl" (psr.aml is generated as a result) - If parameter "-vw 6084" is not supported by your iASL compiler, - please try a newer version. - f) mount debugfs by "mount -t debugfs none /sys/kernel/debug" - g) override the old method via the debugfs by running - "cat /tmp/psr.aml > /sys/kernel/debug/acpi/custom_method" - -2. insert a new method - This is easier than overriding an existing method. - We just need to create the ASL code of the method we want to - insert and then follow the step c) ~ g) in section 1. - -3. undo your changes - The "undo" operation is not supported for a new inserted method - right now, i.e. we can not remove a method currently. - For an overridden method, in order to undo your changes, please - save a copy of the method original ASL code in step c) section 1, - and redo step c) ~ g) to override the method with the original one. - - -Note: We can use a kernel with multiple custom ACPI method running, - But each individual write to debugfs can implement a SINGLE - method override. i.e. if we want to insert/override multiple - ACPI methods, we need to redo step c) ~ g) for multiple times. - -Note: Be aware that root can mis-use this driver to modify arbitrary - memory and gain additional rights, if root's privileges got - restricted (for example if root is not allowed to load additional - modules after boot). |