1.\" 2.\" Copyright (c) 2001 Michael Smith 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd August 16, 2012 29.Dt ACPI 4 30.Os 31.Sh NAME 32.Nm acpi 33.Nd Advanced Configuration and Power Management support 34.Sh SYNOPSIS 35.Cd "device acpi" 36.Pp 37.Cd "options ACPI_DEBUG" 38.Cd "options DDB" 39.Sh DESCRIPTION 40The 41.Nm 42driver provides support for the Intel/Microsoft/Compaq/Toshiba ACPI 43standard. 44This support includes platform hardware discovery (superseding the 45PnP and PCI BIOS), as well as power management (superseding APM) and 46other features. 47ACPI core support is provided by the ACPI CA reference implementation 48from Intel. 49.Pp 50Note that the 51.Nm 52driver is automatically loaded by the 53.Xr loader 8 , 54and should only be 55compiled into the kernel on platforms where ACPI is mandatory. 56.Sh SYSCTL VARIABLES 57The 58.Nm 59driver is intended to provide power management without user intervention. 60If the default settings are not optimal, the following sysctls can be 61used to modify or monitor 62.Nm 63behavior. 64.Bl -tag -width indent 65.It Va debug.acpi.enable_debug_objects 66Enable dumping Debug objects without 67.Cd "options ACPI_DEBUG" . 68Default is 0, ignore Debug objects. 69.It Va hw.acpi.acline 70AC line state (1 means online, 0 means on battery power). 71.It Va hw.acpi.cpu.cx_usage 72Debugging information listing the percent of total usage for each sleep state. 73The values are reset when 74.Va hw.acpi.cpu.cx_lowest 75is modified. 76.It Va hw.acpi.cpu.cx_lowest 77Lowest Cx state to use for idling the CPU. 78A scheduling algorithm will select states between 79.Li C1 80and this setting 81as system load dictates. 82To enable ACPI CPU idling control, 83.Va machdep.cpu_idle_hlt 84must be set to 1. 85.It Va hw.acpi.cpu.cx_supported 86List of supported CPU idle states and their transition latency 87in microseconds. 88Each state has a type (e.g., 89.Li C2 ) . 90.Li C1 91is equivalent to the ia32 92.Li HLT 93instruction, 94.Li C2 95provides a deeper 96sleep with the same semantics, and 97.Li C3 98provides the deepest sleep 99but additionally requires bus mastering to be disabled. 100States greater than 101.Li C3 102provide even more power savings with the same 103semantics as the 104.Li C3 105state. 106Deeper sleeps provide more power savings but increased transition 107latency when an interrupt occurs. 108.It Va hw.acpi.disable_on_reboot 109Disable ACPI during the reboot process. 110Most systems reboot fine with ACPI still enabled, but some require 111exiting to legacy mode first. 112Default is 0, leave ACPI enabled. 113.It Va hw.acpi.handle_reboot 114Use the ACPI Reset Register capability to reboot the system. 115Some newer systems require use of this register, while some only work 116with legacy rebooting support. 117.It Va hw.acpi.lid_switch_state 118Suspend state 119.Pq Li S1 Ns \[en] Ns Li S5 120to enter when the lid switch (i.e., a notebook screen) is closed. 121Default is 122.Dq Li NONE 123(do nothing). 124.It Va hw.acpi.power_button_state 125Suspend state 126.Pq Li S1 Ns \[en] Ns Li S5 127to enter when the power button is pressed. 128Default is 129.Li S5 130(power-off nicely). 131.It Va hw.acpi.reset_video 132Reset the video adapter from real mode during the resume path. 133Some systems need this help, others have display problems if it is enabled. 134Default is 0 (disabled). 135.It Va hw.acpi.s4bios 136Indicate whether the system supports 137.Li S4BIOS . 138This means that the BIOS can handle all the functions of suspending the 139system to disk. 140Otherwise, the OS is responsible for suspending to disk 141.Pq Li S4OS . 142Most current systems do not support 143.Li S4BIOS . 144.It Va hw.acpi.sleep_button_state 145Suspend state 146.Pq Li S1 Ns \[en] Ns Li S5 147to enter when the sleep button is pressed. 148This is usually a special function button on the keyboard. 149Default is 150.Li S3 151(suspend-to-RAM). 152.It Va hw.acpi.sleep_delay 153Wait this number of seconds between preparing the system to suspend and 154actually entering the suspend state. 155Default is 1 second. 156.It Va hw.acpi.supported_sleep_state 157Suspend states 158.Pq Li S1 Ns \[en] Ns Li S5 159supported by the BIOS. 160.Bl -tag -width indent 161.It Li S1 162Quick suspend to RAM. 163The CPU enters a lower power state, but most peripherals are left running. 164.It Li S2 165Lower power state than 166.Li S1 , 167but with the same basic characteristics. 168Not supported by many systems. 169.It Li S3 170Suspend to RAM. 171Most devices are powered off, and the system stops running except for 172memory refresh. 173.It Li S4 174Suspend to disk. 175All devices are powered off, and the system stops running. 176When resuming, the system starts as if from a cold power on. 177Not yet supported by 178.Fx 179unless 180.Li S4BIOS 181is available. 182.It Li S5 183System shuts down cleanly and powers off. 184.El 185.It Va hw.acpi.verbose 186Enable verbose printing from the various ACPI subsystems. 187.El 188.Sh LOADER TUNABLES 189Tunables can be set at the 190.Xr loader 8 191prompt before booting the kernel or stored in 192.Pa /boot/loader.conf . 193Many of these tunables also have a matching 194.Xr sysctl 8 195entry for access after boot. 196.Bl -tag -width indent 197.It Va acpi_dsdt_load 198Enables loading of a custom ACPI DSDT. 199.It Va acpi_dsdt_name 200Name of the DSDT table to load, if loading is enabled. 201.It Va debug.acpi.cpu_unordered 202Do not use the MADT to match ACPI Processor objects to CPUs. 203This is needed on a few systems with a buggy BIOS that does not use 204consistent processor IDs. 205Default is 0 (disabled). 206.It Va debug.acpi.disabled 207Selectively disables portions of ACPI for debugging purposes. 208.It Va debug.acpi.interpreter_slack 209Enable less strict ACPI implementations. 210Default is 1, ignore common BIOS mistakes. 211.It Va debug.acpi.max_threads 212Specify the number of task threads that are started on boot. 213Limiting this to 1 may help work around various BIOSes that cannot 214handle parallel requests. 215The default value is 3. 216.It Va debug.acpi.quirks 217Override any automatic quirks completely. 218.It Va debug.acpi.resume_beep 219Beep the PC speaker on resume. 220This can help diagnose suspend/resume problems. 221Default is 0 (disabled). 222.It Va hint.acpi.0.disabled 223Set this to 1 to disable all of ACPI. 224If ACPI has been disabled on your system due to a blacklist entry for your 225BIOS, you can set this to 0 to re-enable ACPI for testing. 226.It Va hw.acpi.ec.poll_timeout 227Delay in milliseconds to wait for the EC to respond. 228Try increasing this number if you get the error 229.Qq Li AE_NO_HARDWARE_RESPONSE . 230.It Va hw.acpi.host_mem_start 231Override the assumed memory starting address for PCI host bridges. 232.It Va hw.acpi.install_interface , hw.acpi.remove_interface 233Install or remove OS interface(s) to control return value of 234.Ql _OSI 235query method. When an OS interface is specified in 236.Va hw.acpi.install_interface , 237.Li _OSI 238query for the interface returns it is 239.Em supported . 240Conversely, when an OS interface is specified in 241.Va hw.acpi.remove_interface , 242.Li _OSI 243query returns it is 244.Em not supported . 245Multiple interfaces can be specified in a comma-separated list and 246any leading white spaces will be ignored. For example, 247.Qq Li FreeBSD, Linux 248is a valid list of two interfaces 249.Qq Li FreeBSD 250and 251.Qq Li Linux . 252.It Va hw.acpi.reset_video 253Enables calling the VESA reset BIOS vector on the resume path. 254This can fix some graphics cards that have problems such as LCD white-out 255after resume. 256Default is 0 (disabled). 257.It Va hw.acpi.serialize_methods 258Allow override of whether methods execute in parallel or not. 259Enable this for serial behavior, which fixes 260.Qq Li AE_ALREADY_EXISTS 261errors for 262AML that really cannot handle parallel method execution. 263It is off by default since this breaks recursive methods and some IBMs use 264such code. 265.It Va hw.acpi.verbose 266Turn on verbose debugging information about what ACPI is doing. 267.It Va hw.pci.link.%s.%d.irq 268Override the interrupt to use for this link and index. 269This capability should be used carefully, and only if a device is not 270working with 271.Nm 272enabled. 273.Qq %s 274is the name of the link (e.g., LNKA). 275.Qq %d 276is the resource index when the link supports multiple IRQs. 277Most PCI links only have one IRQ resource, so the below form should be used. 278.It Va hw.pci.link.%s.irq 279Override the interrupt to use. 280This capability should be used carefully, and only if a device is not 281working with 282.Nm 283enabled. 284.Qq %s 285is the name of the link (e.g., LNKA). 286.El 287.Sh DISABLING ACPI 288Since ACPI support on different platforms varies greatly, there are many 289debugging and tuning options available. 290.Pp 291For machines known not to work with 292.Nm 293enabled, there is a BIOS blacklist. 294Currently, the blacklist only controls whether 295.Nm 296should be disabled or not. 297In the future, it will have more granularity to control features (the 298infrastructure for that is already there). 299.Pp 300To enable 301.Nm 302(for debugging purposes, etc.) on machines that are on the blacklist, set the 303kernel environment variable 304.Va hint.acpi.0.disabled 305to 0. 306Before trying this, consider updating your BIOS to a more recent version that 307may be compatible with ACPI. 308.Pp 309To disable the 310.Nm 311driver completely, set the kernel environment variable 312.Va hint.acpi.0.disabled 313to 1. 314.Pp 315Some i386 machines totally fail to operate with some or all of ACPI disabled. 316Other i386 machines fail with ACPI enabled. 317Disabling all or part of ACPI on non-i386 platforms (i.e., platforms where 318ACPI support is mandatory) may result in a non-functional system. 319.Pp 320The 321.Nm 322driver comprises a set of drivers, which may be selectively disabled 323in case of problems. 324To disable a sub-driver, list it in the kernel 325environment variable 326.Va debug.acpi.disabled . 327Multiple entries can be listed, separated by a space. 328.Pp 329ACPI sub-devices and features that can be disabled: 330.Bl -tag -width ".Li sysresource" 331.It Li all 332Disable all ACPI features and devices. 333.It Li acad 334.Pq Vt device 335Supports AC adapter. 336.It Li bus 337.Pq Vt feature 338Probes and attaches subdevices. 339Disabling will avoid scanning the ACPI namespace entirely. 340.It Li children 341.Pq Vt feature 342Attaches standard ACPI sub-drivers and devices enumerated in the 343ACPI namespace. 344Disabling this has a similar effect to disabling 345.Dq Li bus , 346except that the 347ACPI namespace will still be scanned. 348.It Li button 349.Pq Vt device 350Supports ACPI button devices (typically power and sleep buttons). 351.It Li cmbat 352.Pq Vt device 353Control-method batteries device. 354.It Li cpu 355.Pq Vt device 356Supports CPU power-saving and speed-setting functions. 357.It Li ec 358.Pq Vt device 359Supports the ACPI Embedded Controller interface, used to communicate 360with embedded platform controllers. 361.It Li isa 362.Pq Vt device 363Supports an ISA bus bridge defined in the ACPI namespace, 364typically as a child of a PCI bus. 365.It Li lid 366.Pq Vt device 367Supports an ACPI laptop lid switch, which typically puts a 368system to sleep. 369.It Li quirks 370.Pq Vt feature 371Do not honor quirks. 372Quirks automatically disable ACPI functionality based on the XSDT table's 373OEM vendor name and revision date. 374.It Li pci 375.Pq Vt device 376Supports Host to PCI bridges. 377.It Li pci_link 378.Pq Vt feature 379Performs PCI interrupt routing. 380.It Li sysresource 381.Pq Vt device 382Pseudo-devices containing resources which ACPI claims. 383.It Li thermal 384.Pq Vt device 385Supports system cooling and heat management. 386.It Li timer 387.Pq Vt device 388Implements a timecounter using the ACPI fixed-frequency timer. 389.It Li video 390.Pq Vt device 391Supports 392.Xr acpi_video 4 393which may conflict with 394.Xr agp 4 395device. 396.El 397.Pp 398It is also possible to avoid portions of the ACPI namespace which 399may be causing problems, by listing the full path of the root of 400the region to be avoided in the kernel environment variable 401.Va debug.acpi.avoid . 402The object and all of its children will be ignored during the 403bus/children scan of the namespace. 404The ACPI CA code will still know about the avoided region. 405.Sh DEBUGGING OUTPUT 406To enable debugging output, 407.Nm 408must be compiled with 409.Cd "options ACPI_DEBUG" . 410Debugging output is separated between layers and levels, where a layer is 411a component of the ACPI subsystem, and a level is a particular kind 412of debugging output. 413.Pp 414Both layers and levels are specified as a whitespace-separated list of 415tokens, with layers listed in 416.Va debug.acpi.layer 417and levels in 418.Va debug.acpi.level . 419.Pp 420The first set of layers is for ACPI-CA components, and the second is for 421.Fx 422drivers. 423The ACPI-CA layer descriptions include the prefix for the files they 424refer to. 425The supported layers are: 426.Pp 427.Bl -tag -compact -width ".Li ACPI_CA_DISASSEMBLER" 428.It Li ACPI_UTILITIES 429Utility ("ut") functions 430.It Li ACPI_HARDWARE 431Hardware access ("hw") 432.It Li ACPI_EVENTS 433Event and GPE ("ev") 434.It Li ACPI_TABLES 435Table access ("tb") 436.It Li ACPI_NAMESPACE 437Namespace evaluation ("ns") 438.It Li ACPI_PARSER 439AML parser ("ps") 440.It Li ACPI_DISPATCHER 441Internal representation of interpreter state ("ds") 442.It Li ACPI_EXECUTER 443Execute AML methods ("ex") 444.It Li ACPI_RESOURCES 445Resource parsing ("rs") 446.It Li ACPI_CA_DEBUGGER 447Debugger implementation ("db", "dm") 448.It Li ACPI_OS_SERVICES 449Usermode support routines ("os") 450.It Li ACPI_CA_DISASSEMBLER 451Disassembler implementation (unused) 452.It Li ACPI_ALL_COMPONENTS 453All the above ACPI-CA components 454.It Li ACPI_AC_ADAPTER 455AC adapter driver 456.It Li ACPI_BATTERY 457Control-method battery driver 458.It Li ACPI_BUS 459ACPI, ISA, and PCI bus drivers 460.It Li ACPI_BUTTON 461Power and sleep button driver 462.It Li ACPI_EC 463Embedded controller driver 464.It Li ACPI_FAN 465Fan driver 466.It Li ACPI_OEM 467Platform-specific driver for hotkeys, LED, etc. 468.It Li ACPI_POWER 469Power resource driver 470.It Li ACPI_PROCESSOR 471CPU driver 472.It Li ACPI_THERMAL 473Thermal zone driver 474.It Li ACPI_TIMER 475Timer driver 476.It Li ACPI_ALL_DRIVERS 477All the above 478.Fx 479ACPI drivers 480.El 481.Pp 482The supported levels are: 483.Pp 484.Bl -tag -compact -width ".Li ACPI_LV_AML_DISASSEMBLE" 485.It Li ACPI_LV_INIT 486Initialization progress 487.It Li ACPI_LV_DEBUG_OBJECT 488Stores to objects 489.It Li ACPI_LV_INFO 490General information and progress 491.It Li ACPI_LV_REPAIR 492Repair a common problem with predefined methods 493.It Li ACPI_LV_ALL_EXCEPTIONS 494All the previous levels 495.It Li ACPI_LV_PARSE 496.It Li ACPI_LV_DISPATCH 497.It Li ACPI_LV_EXEC 498.It Li ACPI_LV_NAMES 499.It Li ACPI_LV_OPREGION 500.It Li ACPI_LV_BFIELD 501.It Li ACPI_LV_TABLES 502.It Li ACPI_LV_VALUES 503.It Li ACPI_LV_OBJECTS 504.It Li ACPI_LV_RESOURCES 505.It Li ACPI_LV_USER_REQUESTS 506.It Li ACPI_LV_PACKAGE 507.It Li ACPI_LV_VERBOSITY1 508All the previous levels 509.It Li ACPI_LV_ALLOCATIONS 510.It Li ACPI_LV_FUNCTIONS 511.It Li ACPI_LV_OPTIMIZATIONS 512.It Li ACPI_LV_VERBOSITY2 513All the previous levels 514.It Li ACPI_LV_ALL 515Synonym for 516.Qq Li ACPI_LV_VERBOSITY2 517.It Li ACPI_LV_MUTEX 518.It Li ACPI_LV_THREADS 519.It Li ACPI_LV_IO 520.It Li ACPI_LV_INTERRUPTS 521.It Li ACPI_LV_VERBOSITY3 522All the previous levels 523.It Li ACPI_LV_AML_DISASSEMBLE 524.It Li ACPI_LV_VERBOSE_INFO 525.It Li ACPI_LV_FULL_TABLES 526.It Li ACPI_LV_EVENTS 527.It Li ACPI_LV_VERBOSE 528All levels after 529.Qq Li ACPI_LV_VERBOSITY3 530.It Li ACPI_LV_INIT_NAMES 531.It Li ACPI_LV_LOAD 532.El 533.Pp 534Selection of the appropriate layer and level values is important 535to avoid massive amounts of debugging output. 536For example, the following configuration is a good way to gather initial 537information. 538It enables debug output for both ACPI-CA and the 539.Nm 540driver, printing basic information about errors, warnings, and progress. 541.Bd -literal -offset indent 542debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS" 543debug.acpi.level="ACPI_LV_ALL_EXCEPTIONS" 544.Ed 545.Pp 546Debugging output by the ACPI CA subsystem is prefixed with the 547module name in lowercase, followed by a source line number. 548Output from the 549.Fx Ns -local 550code follows the same format, but 551the module name is uppercased. 552.Sh OVERRIDING YOUR BIOS BYTECODE 553ACPI interprets bytecode named AML 554(ACPI Machine Language) 555provided by the BIOS vendor as a memory image at boot time. 556Sometimes, the AML code contains a bug that does not appear when parsed 557by the Microsoft implementation. 558.Fx 559provides a way to override it with your own AML code to work around 560or debug such problems. 561Note that all AML in your DSDT and any SSDT tables is overridden. 562.Pp 563In order to load your AML code, you must edit 564.Pa /boot/loader.conf 565and include the following lines. 566.Bd -literal -offset indent 567acpi_dsdt_load="YES" 568acpi_dsdt_name="/boot/acpi_dsdt.aml" # You may change this name. 569.Ed 570.Pp 571In order to prepare your AML code, you will need the 572.Xr acpidump 8 573and 574.Xr iasl 8 575utilities and some ACPI knowledge. 576.Sh COMPATIBILITY 577ACPI is only found and supported on i386/ia32, ia64, and amd64. 578.Sh SEE ALSO 579.Xr kenv 1 , 580.Xr acpi_thermal 4 , 581.Xr device.hints 5 , 582.Xr loader.conf 5 , 583.Xr acpiconf 8 , 584.Xr acpidump 8 , 585.Xr config 8 , 586.Xr iasl 8 587.Rs 588.%A "Compaq Computer Corporation" 589.%A "Intel Corporation" 590.%A "Microsoft Corporation" 591.%A "Phoenix Technologies Ltd." 592.%A "Toshiba Corporation" 593.%D August 25, 2003 594.%T "Advanced Configuration and Power Interface Specification" 595.%U http://acpi.info/spec.htm 596.Re 597.Sh AUTHORS 598.An -nosplit 599The ACPI CA subsystem is developed and maintained by 600Intel Architecture Labs. 601.Pp 602The following people made notable contributions to the ACPI subsystem 603in 604.Fx : 605.An Michael Smith , 606.An Takanori Watanabe Aq takawata@jp.FreeBSD.org , 607.An Mitsuru IWASAKI Aq iwasaki@jp.FreeBSD.org , 608.An Munehiro Matsuda , 609.An Nate Lawson , 610the ACPI-jp mailing list at 611.Aq acpi-jp@jp.FreeBSD.org , 612and many other contributors. 613.Pp 614This manual page was written by 615.An Michael Smith Aq msmith@FreeBSD.org . 616.Sh BUGS 617Many BIOS versions have serious bugs that may cause system instability, 618break suspend/resume, or prevent devices from operating properly due to 619IRQ routing problems. 620Upgrade your BIOS to the latest version available from the vendor before 621deciding it is a problem with 622.Nm . 623.Pp 624The 625.Nm 626CPU idle power management drive conflicts with the local APIC (LAPIC) 627timer. 628Disable the local APIC timer with 629.Va hint.apic.0.clock=0 630or do not use the 631.Li C3 632and deeper states if the local APIC timer is enabled. 633