23 Jul, 2018
6 commits
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Instead of port and endpoint properties for representing ports and
endpoints, use the keys of the hierarchical data extension references
when referring to the port and endpoint nodes. Additionally, use "reg"
properties as in Device Tree to specify the number of the port or the
endpoint.The keys of the port nodes begin with "port" and the keys of the endpoint
nodes begin with "endpoint", both followed by "@" character and the number
of the port or the endpoint.These changes have the advantage that no ACPI specific properties need to
be added to refer to non-device nodes. Additionally, using the name of the
node instead of an integer property inside the node is easier to parse in
code and easier for humans to understand.Signed-off-by: Sakari Ailus
Signed-off-by: Rafael J. Wysocki -
Document that if a port has a single endpoint only, its value shall be
zero. Similarly, if a device object only has a single port, its value
shlla be zero.Signed-off-by: Sakari Ailus
Signed-off-by: Rafael J. Wysocki -
Address a few issues in the ACPI _DSD properties graph documentation:
- the extension for port nodes is a data extension (and not property
extension),- clean up language in port hierarchical data extension definition,
- add examples of port and endpoint packages,
- port property value is the number of the "port" and not the number
of the "port node",- remove word "individual" from endpoint data node description, it
was redundant,- remove the extra "The" in the endpoint property description,
- refer to hierarchical data extension keys and targets instead of
first and second package list entries.Signed-off-by: Sakari Ailus
Signed-off-by: Rafael J. Wysocki -
Hierarchical data extension 1.1 allows using references as the second
entries of the hierearchical data extension packages. Update the
references and the examples.The quotes are left in documentation for clarity.
Signed-off-by: Sakari Ailus
Signed-off-by: Rafael J. Wysocki -
As part of the hierarchical data extension key naming, introduce numbering
scheme for the nodes that may be referred to using hierarchical data
extension references. This allows iterating over particular kind of nodes
recognised by the node name whilst allowing numbering the nodes, bringing
ACPI to feature parity with DT in this respect.Signed-off-by: Sakari Ailus
Signed-off-by: Rafael J. Wysocki -
Add documentation on how to refer to hierarchical data nodes in a
generic way. This brings ACPI to feature parity with Device Tree in
terms of being able to refer to any node in the tree.Signed-off-by: Sakari Ailus
Signed-off-by: Rafael J. Wysocki
06 Jun, 2018
1 commit
-
Reviewed-by: Changzhong Li
Reviewed-by: Rui Zhang
Signed-off-by: Erik Schmauss
Signed-off-by: Rafael J. Wysocki
24 Apr, 2018
1 commit
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Add a file to describe the CPPC sysfs interface and steps to compute
average delivered performance using the feedback counters.Signed-off-by: Prashanth Prakash
[ rjw: Minor adjustments ]
Signed-off-by: Rafael J. Wysocki
11 Oct, 2017
1 commit
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Add functionality to read LPIT table, which provides:
- Sysfs interface to read residency counters via
/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us
/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_usHere the count "low_power_idle_cpu_residency_us" shows the time spent
by CPU package in low power state. This is read via MSR interface,
which points to MSR for PKG C10.Here the count "low_power_idle_system_residency_us" show the count the
system was in low power state. This is read via MMIO interface. This
is mapped to SLP_S0 residency on modern Intel systems. This residency
is achieved only when CPU is in PKG C10 and all functional blocks are
in low power state.It is possible that none of the above counters present or anyone of the
counter present or all counters present.For example: On my Kabylake system both of the above counters present.
After suspend to idle these counts updated and prints:6916179
6998564This counter can be read by tools like turbostat to display. Or it can
be used to debug, if modern systems are reaching desired low power state.- Provides an interface to read residency counter memory address
This address can be used to get the base address of PMC memory
mapped IO. This is utilized by intel_pmc_core driver to print
more debug information.In addition, to avoid code duplication to read iomem, removed the read of
iomem from acpi_os_read_memory() in osl.c and made a common function
acpi_os_read_iomem(). This new function is used for reading iomem in
in both osl.c and acpi_lpit.c.Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf
Signed-off-by: Srinivas Pandruvada
Signed-off-by: Rafael J. Wysocki
08 Jul, 2017
1 commit
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Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.13 series.Some administrativa:
I have a slew of 8250 serial patches and the new IOT2040 serial+GPIO
driver coming in through this tree, along with a whole bunch of Exar
8250 fixes. These are ACKed by Greg and also hit drivers/platform/*
where they are ACKed by Andy Shevchenko.Speaking about drivers/platform/* there is also a bunch of ACPI stuff
coming through that route, again ACKed by Andy.The MCP23S08 changes are coming in here as well. You already have the
commits in your tree, so this is just a result of sharing an immutable
branch between pin control and GPIO.Core:
- Export add/remove for lookup tables so that modules can export GPIO
descriptor tables.
- Handle GPIO sleep states: it is now possible to flag that a GPIO
line may loose its state during suspend/resume of the system to
save power. This is used in the Wolfson Micro Arizona driver.
- ACPI-based GPIO was tightened up a lot around the edges.
- Use bitmap_fill() to speed up a loop.New drivers:
- Exar XRA1403 SPI-based GPIO.
- MVEBU driver now supports Armada 7K and 8K.
- LP87565 PMIC GPIO.
- Renesas R-CAR R8A7743 (RZ/G1M).
- The new IOT2040 8250 serial/GPIO also comes in through this
changeset.Substantial driver changes:
- Seriously fix the Exar 8250 GPIO portions to work.
- The MCP23S08 was moved out to a pin control driver.
- Convert MEVEBU to use regmap for register access.
- Drop Vulcan support from the Broadcom driver.
- Serious cleanup and improvement of the mockup driver, giving us a
better test coverage.Misc:
- Lots of janitorial clean up.
- A bunch of documentation fixes"* tag 'gpio-v4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (70 commits)
serial: exar: Add support for IOT2040 device
gpio-exar/8250-exar: Make set of exported GPIOs configurable
platform: Accept const properties
serial: exar: Factor out platform hooks
gpio-exar/8250-exar: Rearrange gpiochip parenthood
gpio: exar: Fix iomap request
gpio-exar/8250-exar: Do not even instantiate a GPIO device for Commtech cards
serial: uapi: Add support for bus termination
gpio: rcar: Add R8A7743 (RZ/G1M) support
gpio: gpio-wcove: Fix GPIO control register offset calculation
gpio: lp87565: Add support for GPIO
gpio: dwapb: fix missing first irq for edgeboth irq type
MAINTAINERS: Take maintainership for GPIO ACPI support
gpio: exar: Fix reading of directions and values
gpio: exar: Allocate resources on behalf of the platform device
gpio-exar/8250-exar: Fix passing in of parent PCI device
gpio: mockup: use devm_kcalloc() where applicable
gpio: mockup: add myself as author
gpio: mockup: improve the error message
gpio: mockup: don't return magic numbers from probe()
...
29 May, 2017
1 commit
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Documentation lacks of explanation how we actually use device properties
for GPIO resources.Add a section to the documentation about that.
Suggested-by: Mika Westerberg
Signed-off-by: Andy Shevchenko
Tested-by: Jarkko Nikula
Reviewed-by: Mika Westerberg
Signed-off-by: Linus Walleij
23 May, 2017
1 commit
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* acpi-button:
Revert "ACPI / button: Remove lid_init_state=method mode"* acpi-tools:
tools/power/acpi: Add .gitignore file
13 May, 2017
1 commit
-
This reverts commit ecb10b694b72ca5ea51b3c90a71ff2a11963425a.
The only expected ACPI control method lid device's usage model is
1. Listen to the lid notification,
2. Evaluate _LID after being notified by BIOS,
3. Suspend the system (if users configure to do so) after seeing "close".It's not ensured that BIOS will notify OS after boot/resume, and
it's not ensured that BIOS will always generate "open" event upon
opening the lid.But there are 2 wrong usage models:
1. When the lid device is responsible for suspend/resume the system,
userspace requires to see "open" event to be paired with "close" after
the system is resumed, or it will suspend the system again.2. When an external monitor connects to the laptop attached docks,
userspace requires to see "close" event after the system is resumed so
that it can determine whether the internal display should remain dark
and the external display should be lit on.After we made default kernel behavior to be suitable for usage model 1,
users of usage model 2 start to report regressions for such behavior
change.Reversion of button.lid_init_state=method doesn't actually reverts to old
default behavior as doing so can enter a regression loop, but facilitates
users to work the reported regressions around with
button.lid_init_state=method.Fixes: ecb10b694b72 (ACPI / button: Remove lid_init_state=method mode)
Cc: 4.11+ # 4.11+
Link: https://bugzilla.kernel.org/show_bug.cgi?id=195455
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1430259
Tested-by: Steffen Weber
Tested-by: Julian Wiedmann
Reported-by: Joachim Frieben
Signed-off-by: Lv Zheng
Signed-off-by: Rafael J. Wysocki
03 May, 2017
1 commit
-
Pull documentation update from Jonathan Corbet:
"A reasonably busy cycle for documentation this time around. There is a
new guide for user-space API documents, rather sparsely populated at
the moment, but it's a start. Markus improved the infrastructure for
converting diagrams. Mauro has converted much of the USB documentation
over to RST. Plus the usual set of fixes, improvements, and tweaks.There's a bit more than the usual amount of reaching out of
Documentation/ to fix comments elsewhere in the tree; I have acks for
those where I could get them"* tag 'docs-4.12' of git://git.lwn.net/linux: (74 commits)
docs: Fix a couple typos
docs: Fix a spelling error in vfio-mediated-device.txt
docs: Fix a spelling error in ioctl-number.txt
MAINTAINERS: update file entry for HSI subsystem
Documentation: allow installing man pages to a user defined directory
Doc/PM: Sync with intel_powerclamp code behavior
zr364xx.rst: usb/devices is now at /sys/kernel/debug/
usb.rst: move documentation from proc_usb_info.txt to USB ReST book
convert philips.txt to ReST and add to media docs
docs-rst: usb: update old usbfs-related documentation
arm: Documentation: update a path name
docs: process/4.Coding.rst: Fix a couple of document refs
docs-rst: fix usb cross-references
usb: gadget.h: be consistent at kernel doc macros
usb: composite.h: fix two warnings when building docs
usb: get rid of some ReST doc build errors
usb.rst: get rid of some Sphinx errors
usb/URB.txt: convert to ReST and update it
usb/persist.txt: convert to ReST and add to driver-api book
usb/hotplug.txt: convert to ReST and add to driver-api book
...
02 May, 2017
1 commit
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Pull generic device properties framework updates from Rafael Wysocki:
"These add support for the ports and endpoints concepts, based on the
existing DT support for them, to the generic device properties
framework and update the ACPI _DSD properties code to recognize ports
and endpoints accordingly.Specifics:
- Extend the ACPI _DSD properties code and the generic device
properties framework to support the concept of remote endponts
(Mika Westerberg, Sakari Ailus).- Document the support for ports and endpoints in _DSD properties and
extend the generic device properties framework to make it more
suitable for the handling of ports and endpoints (Sakari Ailus)"* tag 'devprop-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
device property: Read strings using string array reading functions
device property: fwnode_property_read_string_array() returns nr of strings
device property: Fix reading pset strings using array access functions
device property: fwnode_property_read_string_array() may return -EILSEQ
ACPI / DSD: Document references, ports and endpoints
device property: Add fwnode_get_next_parent()
device property: Add support for fwnode endpoints
device property: Make dev_fwnode() public
of: Add of_fwnode_handle() to convert device nodes to fwnode_handle
device property: Add fwnode_handle_get()
device property: Add support for remote endpoints
ACPI / property: Add support for remote endpoints
device property: Add fwnode_get_named_child_node()
ACPI / property: Add fwnode_get_next_child_node()
device property: Add fwnode_get_parent()
ACPI / property: Add possiblity to retrieve parent firmware node
19 Apr, 2017
1 commit
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Fix some typos in the linuxized-acpica.txt document.
Signed-off-by: Cao jin
[ rjw: Subject / changelog ]
Signed-off-by: Rafael J. Wysocki
29 Mar, 2017
1 commit
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Document the use of references into the hierarchical data extension
structure, as well as the use of port and endpoint concepts that are very
similar to those in Devicetree.Signed-off-by: Sakari Ailus
Reviewed-by: Mika Westerberg
Signed-off-by: Rafael J. Wysocki
18 Mar, 2017
1 commit
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Fix typos in acpi directory to make documentation grammatically correct.
Signed-off-by: Tamara Diaconita
Signed-off-by: Jonathan Corbet
28 Feb, 2017
2 commits
-
Fix typos and add the following to the scripts/spelling.txt:
followings||following
While we are here, add a missing colon in the boilerplate in DT binding
documents. The "you SoC" in allwinner,sunxi-pinctrl.txt was fixed as
well.I reworded "as the followings:" to "as follows:" for
drivers/usb/gadget/udc/renesas_usb3.c.Link: http://lkml.kernel.org/r/1481573103-11329-32-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix typos and add the following to the scripts/spelling.txt:
overrided||overridden
Link: http://lkml.kernel.org/r/1481573103-11329-22-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Feb, 2017
1 commit
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The mode is buggy, and lid_init__state=open is more useful than this
mode, so this patch makes it deprecated.Signed-off-by: Lv Zheng
Signed-off-by: Rafael J. Wysocki
14 Dec, 2016
1 commit
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Pull ACPI updates from Rafael Wysocki:
"The ACPICA code in the kernel gets updated as usual (included is
upstream revision 20160930 and a few commits from the next one, with
the rest waiting for an issue discovered in linux-next to be
addressed) which brings in a couple of fixes and cleanupsOn top of that initial support for APEI on ARM64 is added, two new
pieces of documentation are introduced, the properties-parsing code is
updated to follow changes in the (external) documentation it is based
on and there are a few updates of SoC drivers, some new blacklist
entries, plus some assorted fixes and cleanupsSpecifics:
- ACPICA update including upstream revision 20160930 and several
commits beyond it (Bob Moore, Lv Zheng)- Initial support for ACPI APEI on ARM64 (Tomasz Nowicki)
- New document describing the handling of _OSI and _REV in Linux (Len
Brown)- New document describing the usage rules for _DSD properties (Rafael
Wysocki)- Update of the ACPI properties-parsing code to reflect recent
changes in the (external) documentation it is based on (Rafael
Wysocki)- Updates of the ACPI LPSS and ACPI APD SoC drivers for additional
hardware support (Andy Shevchenko, Nehal Shah)- New blacklist entries for _REV and video handling (Alex Hung, Hans
de Goede, Michael Pobega)- ACPI battery driver fix to fall back to _BIF if _BIX fails (Dave
Lambley)- NMI notifications handling fix for APEI (Prarit Bhargava)
- Error code path fix for the ACPI CPPC library (Dan Carpenter)
- Assorted cleanups (Andy Shevchenko, Longpeng Mike)"
* tag 'acpi-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (31 commits)
ACPICA: Utilities: Add new decode function for parser values
ACPI / osl: Refactor acpi_os_get_root_pointer() to drop 'else':s
ACPI / osl: Propagate actual error code for kstrtoul()
ACPI / property: Document usage rules for _DSD properties
ACPI: Document _OSI and _REV for Linux BIOS writers
ACPI / APEI / ARM64: APEI initial support for ARM64
ACPI / APEI: Fix NMI notification handling
ACPICA: Tables: Add an error message complaining driver bugs
ACPICA: Tables: Add acpi_tb_unload_table()
ACPICA: Tables: Cleanup acpi_tb_install_and_load_table()
ACPICA: Events: Fix acpi_ev_initialize_region() return value
ACPICA: Back port of "ACPICA: Dispatcher: Tune interpreter lock around AcpiEvInitializeRegion()"
ACPICA: Namespace: Add acpi_ns_handle_to_name()
ACPI / CPPC: set an error code on probe error path
ACPI / video: Add force_native quirk for HP Pavilion dv6
ACPI / video: Add force_native quirk for Dell XPS 17 L702X
ACPI / property: Hierarchical properties support update
ACPI / LPSS: enable hard LLP for DMA
ACPI / battery: If _BIX fails, retry with _BIF
ACPI / video: Move ACPI_VIDEO_NOTIFY_* defines to acpi/video.h
..
13 Dec, 2016
2 commits
-
Pull GPIO updates from Luinus Walleij:
"Bulk GPIO changes for the v4.10 kernel cycle:Core changes:
- Simplify threaded interrupt handling: instead of passing numbed
parameters to gpiochip_irqchip_add_chained() we create a new call:
gpiochip_irqchip_add_nested() so the two types are clearly
semantically different. Also make sure that all nested chips call
gpiochip_set_nested_irqchip() which is necessary for IRQ resend to
work properly if it happens.- Return error on seek operations for the chardev.
- Clamp values set as part of gpio[d]_direction_output() so that
anything != 0 will be send down to the driver as "1" not the value
passed in.- ACPI can now support naming of GPIO lines, hogs and holes in the
GPIO lists.New drivers:
- The SX150x driver was deemed unfit for the GPIO subsystem and was
moved over to a combined GPIO+pinctrl driver in the pinctrl
subsystem.New features:
- Various cleanups to various drivers"
* tag 'gpio-v4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (49 commits)
gpio: merrifield: Implement gpio_get_direction callback
gpio: merrifield: Add support for hardware debouncer
gpio: chardev: Return error for seek operations
gpio: arizona: Tidy up probe error path
gpio: arizona: Remove pointless set of platform drvdata
gpio: pl061: delete platform data handling
gpio: pl061: move platform data into driver
gpio: pl061: rename variable from chip to pl061
gpio: pl061: rename state container struct
gpio: pl061: use local state for parent IRQ storage
gpio: set explicit nesting on drivers
gpio: simplify adding threaded interrupts
gpio: vf610: use builtin_platform_driver
gpio: axp209: use correct register for GPIO input status
gpio: stmpe: fix interrupt handling bug
gpio: em: depnd on ARCH_SHMOBILE
gpio: zx: depend on ARCH_ZX
gpio: x86: update config dependencies for x86 specific hardware
gpio: mb86s7x: use builtin_platform_driver
gpio: etraxfs: use builtin_platform_driver
... -
* device-properties:
ACPI / property: Document usage rules for _DSD properties
ACPI / property: Hierarchical properties support update
06 Dec, 2016
1 commit
-
Following some discussions during the Kernel Summit and LPC, document
what can be returned from ACPI _DSD as device properties and when it
is valid to use the special PRP0001 device ID.Signed-off-by: Rafael J. Wysocki
Reviewed-by: Mika Westerberg
Acked-by: Andy Shevchenko
Reviwed-by: Mark Brown
03 Dec, 2016
1 commit
-
Based on a recent session at the Linux Plumber's Conference,
we need to be more clear about how a BIOS should use _OSI
to properly support Linux.Signed-off-by: Len Brown
Reviewed-by: Lukas Wunner
Signed-off-by: Rafael J. Wysocki
24 Oct, 2016
4 commits
-
Now that we have the new helper function that sets nice names for GPIO
lines based on "gpio-line-names" device property, we can take advantage of
this in acpi_gpiochip_add().Signed-off-by: Mika Westerberg
Signed-off-by: Linus Walleij -
GPIO hogging means that the GPIO controller can "hog" and configure certain
GPIOs without need for a driver or userspace to do that. This is useful in
open-connected boards where BIOS cannot possibly know beforehand which
devices will be connected to the board.This adds GPIO hogging mechanism to ACPI analogous to Device Tree.
Signed-off-by: Mika Westerberg
Acked-by: Rafael J. Wysocki
Signed-off-by: Linus Walleij -
Make it possible to have an empty GPIOs in a GPIO list for device. For
example a SPI master may use both GPIOs and native pins as chip selects and
we need to be able to distinguish between the two.This makes it mandatory to have exactly 3 arguments for GPIOs and then
converts gpiolib to use of __acpi_node_get_property_reference() instead. In
addition we make acpi_gpio_package_count() to handle holes as well (this
matches the DT version).Signed-off-by: Mika Westerberg
Acked-by: Rafael J. Wysocki
Signed-off-by: Linus Walleij -
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.Signed-off-by: Mauro Carvalho Chehab
02 Oct, 2016
1 commit
-
* acpi-button:
ACPI / button: Add document for ACPI control method lid device restrictions
ACPI / button: Fix an issue in button.lid_init_state=ignore mode* acpi-battery:
ACPI / battery: Add sysfs representation after checking _BST* acpi-doc:
ACPI / documentation: Use recommended name in GPIO property names
29 Sep, 2016
1 commit
-
The recommended property name for all kinds of GPIOs is to end it with
"-gpios" even if there is only one GPIO. Update the documentation to follow
this fact.Signed-off-by: Mika Westerberg
Signed-off-by: Rafael J. Wysocki
31 Aug, 2016
1 commit
-
This patch adds documentation for the usage model of the control method lid
device on some buggy platforms.Signed-off-by: Lv Zheng
Acked-by: Benjamin Tissoires
Signed-off-by: Rafael J. Wysocki
25 Jul, 2016
1 commit
-
* acpi-bus:
ACPI / bus: Support for platform initiated graceful shutdown
ACPI / bus: Correct the comments about acpi_subsystem_init()
ACPI / bus: Use acpi_handle_debug() in acpi_print_osc_error()* acpi-pci:
ACPI / PCI: make pci_slot explicitly non-modular
ACPI / PCI: pci_slot: Use generic pr_debug utility
ACPI / PCI: pci_slot: Use more common logging style* acpica:
ACPICA: Linux: Enable ACPI_MUTEX_DEBUG for Linux kernel* acpi-doc:
ACPI / debugger: Add AML debugger documentation
ACPI: Add documentation describing ACPICA release automation
09 Jul, 2016
5 commits
-
This patch documents the AML debugger.
Signed-off-by: Lv Zheng
[ rjw: Editorial changes ]
Signed-off-by: Rafael J. Wysocki -
This patch documents the ACPICA release automation.
Signed-off-by: Lv Zheng
[ rjw: Editorial changes ]
Signed-off-by: Rafael J. Wysocki -
New tables can be loaded by creating directories under /config/table/
and writing the AML code into the aml table attribute. Various table
attributes will be readable once the table is successfully loaded.Unloading tables is not supported at the moment, but it can be easily
implemented once ACPI loading functions provide a table handle to be
used for unloading.Signed-off-by: Octavian Purdila
Reviewed-by: Mika Westerberg
Signed-off-by: Rafael J. Wysocki -
This patch allows SSDTs to be loaded from EFI variables. It works by
specifying the EFI variable name containing the SSDT to be loaded. All
variables with the same name (regardless of the vendor GUID) will be
loaded.Note that we can't use acpi_install_table and we must rely on the
dynamic ACPI table loading and bus re-scanning mechanisms. That is
because I2C/SPI controllers are initialized earlier then the EFI
subsystems and all I2C/SPI ACPI devices are enumerated when the
I2C/SPI controllers are initialized.Signed-off-by: Octavian Purdila
Reviewed-by: Matt Fleming
Signed-off-by: Rafael J. Wysocki -
Signed-off-by: Octavian Purdila
Reviewed-by: Mika Westerberg
Signed-off-by: Rafael J. Wysocki
19 Apr, 2016
1 commit
-
This patch converts the initrd table override mechanism to the table
upgrade mechanism by restricting its usage to the tables released with
compatibility and more recent revision.This use case has been encouraged by the ACPI specification:
1. OEMID:
An OEM-supplied string that identifies the OEM.2. OEM Table ID:
An OEM-supplied string that the OEM uses to identify the particular data
table. This field is particularly useful when defining a definition
block to distinguish definition block functions. OEM assigns each
dissimilar table a new OEM Table Id.3. OEM Revision:
An OEM-supplied revision number. Larger numbers are assumed to be newer
revisions.For OEMs, good practices will ensure consistency when assigning OEMID and
OEM Table ID fields in any table. The intent of these fields is to allow
for a binary control system that support services can use. Because many
support function can be automated, it is useful when a tool can
programatically determine which table release is a compatible and more
recent revision of a prior table on the same OEMID and OEM Table ID.The facility can now be used by the vendors to upgrade wrong tables for bug
fixing purpose, thus lockdep disabling taint is not suitable for it and it
should be a default 'y' option to implement the spec encouraged use case.Note that, by implementing table upgrade inside of ACPICA itself, it is
possible to remove acpi_table_initrd_override() and tables can be upgraded
by acpi_install_table() automatically. Though current ACPICA impelentation
hasn't implemented this, this patched changes the table flag setting timing
to allow this to be implemented in ACPICA without changing the code here.Documentation of initrd override mechanism is upgraded accordingly.
Original-by: Octavian Purdila
Signed-off-by: Lv Zheng
Signed-off-by: Rafael J. Wysocki