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 February 13, 2005 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. 60Thus, some of these sysctls are controlled automatically by the 61.Pa power_profile 62.Xr rc 8 63script, which can be configured via 64.Xr rc.conf 5 . 65If values are specified manually, they may be overridden. 66.Bl -tag -width indent 67.It Va hw.acpi.cpu.cx_usage 68Debugging information listing the percent of total usage for each sleep state. 69The values are reset when 70.Va hw.acpi.cpu.cx_lowest 71is modified. 72.It Va hw.acpi.cpu.cx_lowest 73Lowest Cx state to use for idling the CPU. 74A scheduling algorithm will select states between C1 and this setting 75as system load dictates. 76To enable ACPI CPU idling control, 77.Va machdep.cpu_idle_hlt 78must be set to 1. 79.It Va hw.acpi.cpu.cx_supported 80List of supported CPU idle states and their transition latency 81in microseconds. 82Each state has a type (e.g., C2). 83C1 is equivalent to the ia32 HLT instruction, C2 provides a deeper 84sleep with the same semantics, and C3 provides the deepest sleep 85but additionally requires bus mastering to be disabled. 86States greater than C3 provide even more power savings with the same 87semantics as the C3 state. 88Deeper sleeps provide more power savings but increased transition 89latency when an interrupt occurs. 90.El 91.Sh LOADER TUNABLES 92Tunables can be set at the 93.Xr loader 8 94prompt before booting the kernel or stored in 95.Pa /boot/loader.conf . 96.Bl -tag -width indent 97.It Va acpi_dsdt_load 98Enables loading of a custom ACPI DSDT. 99.It Va acpi_dsdt_name 100Name of the DSDT table to load, if loading is enabled. 101.It Va debug.acpi.disabled 102Selectively disables portions of ACPI for debugging purposes. 103.It Va debug.acpi.max_threads 104Specify the number of task threads that are started on boot. 105Limiting this to 1 may help work around various BIOSes that cannot 106handle parallel requests. 107The default value is 3. 108.It Va debug.acpi.quirks 109Override any automatic quirks completely. 110.It Va hint.acpi.0.disabled 111Set this to 1 to disable all of ACPI. 112If ACPI has been disabled on your system due to a blacklist entry for your 113BIOS, you can set this to 0 to re-enable ACPI for testing. 114.It Va hw.acpi.ec.poll_timeout 115Delay in milliseconds to wait for the EC to respond. 116Try increasing this number if you get the error 117.Qq Li AE_NO_HARDWARE_RESPONSE . 118.It Va hw.acpi.host_mem_start 119Override the assumed memory starting address for PCI host bridges. 120.It Va hw.acpi.pci.link.%d.%d.%d.irq 121Override the interrupt to use. 122.It Va hw.acpi.reset_video 123Enables calling the VESA reset BIOS vector on the resume path. 124Some graphic chips have problems such as LCD white-out after resume. 125Try setting this to 0 if this causes problems for you. 126.It Va hw.acpi.serialize_methods 127Allow override of whether methods execute in parallel or not. 128Enable this for serial behavior, which fixes 129.Qq Li AE_ALREADY_EXISTS 130errors for 131AML that really cannot handle parallel method execution. 132It is off by default since this breaks recursive methods and some IBMs use 133such code. 134.It Va hw.acpi.verbose 135Turn on verbose debugging information about what ACPI is doing. 136.El 137.Sh DISABLING ACPI 138Since ACPI support on different platforms varies greatly, there are many 139debugging and tuning options available. 140.Pp 141For machines known not to work with 142.Nm 143enabled, there is a BIOS blacklist. 144Currently, the blacklist only controls whether 145.Nm 146should be disabled or not. 147In the future, it will have more granularity to control features (the 148infrastructure for that is already there). 149.Pp 150To enable 151.Nm 152(for debugging purposes, etc.) on machines that are on the blacklist, set the 153kernel environment variable 154.Va hint.acpi.0.disabled 155to 0. 156Before trying this, consider updating your BIOS to a more recent version that 157may be compatible with ACPI. 158.Pp 159To disable the 160.Nm 161driver completely, set the kernel environment variable 162.Va hint.acpi.0.disabled 163to 1. 164.Pp 165Some i386 machines totally fail to operate with some or all of ACPI disabled. 166Other i386 machines fail with ACPI enabled. 167Disabling all or part of ACPI on non-i386 platforms (i.e., platforms where 168ACPI support is mandatory) may result in a non-functional system. 169.Pp 170The 171.Nm 172driver comprises a set of drivers, which may be selectively disabled 173in case of problems. 174To disable a sub-driver, list it in the kernel 175environment variable 176.Va debug.acpi.disabled . 177Multiple entries can be listed, separated by a space. 178.Pp 179ACPI sub-devices and features that can be disabled: 180.Bl -tag -width ".Li sysresource" 181.It Li all 182Disable all ACPI features and devices. 183.It Li acad 184.Pq Vt device 185Supports AC adapter. 186.It Li bus 187.Pq Vt feature 188Probes and attaches subdevices. 189Disabling will avoid scanning the ACPI namespace entirely. 190.It Li children 191.Pq Vt feature 192Attaches standard ACPI sub-drivers and devices enumerated in the 193ACPI namespace. 194Disabling this has a similar effect to disabling 195.Dq Li bus , 196except that the 197ACPI namespace will still be scanned. 198.It Li button 199.Pq Vt device 200Supports ACPI button devices (typically power and sleep buttons). 201.It Li cmbat 202.Pq Vt device 203Control-method batteries device. 204.It Li cpu 205.Pq Vt device 206Supports CPU power-saving and speed-setting functions. 207.It Li ec 208.Pq Vt device 209Supports the ACPI Embedded Controller interface, used to communicate 210with embedded platform controllers. 211.It Li isa 212.Pq Vt device 213Supports an ISA bus bridge defined in the ACPI namespace, 214typically as a child of a PCI bus. 215.It Li lid 216.Pq Vt device 217Supports an ACPI laptop lid switch, which typically puts a 218system to sleep. 219.It Li quirks 220.Pq Vt feature 221Do not honor quirks. 222Quirks automatically disable ACPI functionality based on the XSDT table's 223OEM vendor name and revision date. 224.It Li pci 225.Pq Vt device 226Supports Host to PCI bridges. 227.It Li pci_link 228.Pq Vt feature 229Performs PCI interrupt routing. 230.It Li sysresource 231.Pq Vt device 232Pseudo-devices containing resources which ACPI claims. 233.It Li thermal 234.Pq Vt device 235Supports system cooling and heat management. 236.It Li timer 237.Pq Vt device 238Implements a timecounter using the ACPI fixed-frequency timer. 239.It Li video 240.Pq Vt device 241Supports 242.Xr acpi_video 4 243which may conflict with 244.Xr agp 4 245device. 246.El 247.Pp 248It is also possible to avoid portions of the ACPI namespace which 249may be causing problems, by listing the full path of the root of 250the region to be avoided in the kernel environment variable 251.Va debug.acpi.avoid . 252The object and all of its children will be ignored during the 253bus/children scan of the namespace. 254The ACPI CA code will still know about the avoided region. 255.Sh DEBUGGING OUTPUT 256To enable debugging output, 257.Nm 258must be compiled with 259.Cd "options ACPI_DEBUG" . 260Debugging output is separated between layers and levels, where a layer is 261a component of the ACPI subsystem, and a level is a particular kind 262of debugging output. 263.Pp 264Both layers and levels are specified as a whitespace-separated list of 265tokens, with layers listed in 266.Va debug.acpi.layer 267and levels in 268.Va debug.acpi.level . 269.Pp 270The first set of layers is for ACPI-CA components, and the second is for 271.Fx 272drivers. 273The ACPI-CA layer descriptions include the prefix for the files they 274refer to. 275The supported layers are: 276.Pp 277.Bl -tag -compact -width ".Li ACPI_CA_DISASSEMBLER" 278.It Li ACPI_UTILITIES 279Utility ("ut") functions 280.It Li ACPI_HARDWARE 281Hardware access ("hw") 282.It Li ACPI_EVENTS 283Event and GPE ("ev") 284.It Li ACPI_TABLES 285Table access ("tb") 286.It Li ACPI_NAMESPACE 287Namespace evaluation ("ns") 288.It Li ACPI_PARSER 289AML parser ("ps") 290.It Li ACPI_DISPATCHER 291Internal representation of interpreter state ("ds") 292.It Li ACPI_EXECUTER 293Execute AML methods ("ex") 294.It Li ACPI_RESOURCES 295Resource parsing ("rs") 296.It Li ACPI_CA_DEBUGGER 297Debugger implementation ("db", "dm") 298.It Li ACPI_OS_SERVICES 299Usermode support routines ("os") 300.It Li ACPI_CA_DISASSEMBLER 301Disassembler implementation (unused) 302.It Li ACPI_ALL_COMPONENTS 303All the above ACPI-CA components 304.It Li ACPI_AC_ADAPTER 305AC adapter driver 306.It Li ACPI_BATTERY 307Control-method battery driver 308.It Li ACPI_BUS 309ACPI, ISA, and PCI bus drivers 310.It Li ACPI_BUTTON 311Power and sleep button driver 312.It Li ACPI_EC 313Embedded controller driver 314.It Li ACPI_FAN 315Fan driver 316.It Li ACPI_OEM 317Platform-specific driver for hotkeys, LED, etc. 318.It Li ACPI_POWER 319Power resource driver 320.It Li ACPI_PROCESSOR 321CPU driver 322.It Li ACPI_THERMAL 323Thermal zone driver 324.It Li ACPI_TIMER 325Timer driver 326.It Li ACPI_ALL_DRIVERS 327All the above 328.Fx 329ACPI drivers 330.El 331.Pp 332The supported levels are: 333.Pp 334.Bl -tag -compact -width ".Li ACPI_LV_AML_DISASSEMBLE" 335.It Li ACPI_LV_ERROR 336Fatal error conditions 337.It Li ACPI_LV_WARN 338Warnings and potential problems 339.It Li ACPI_LV_INIT 340Initialization progress 341.It Li ACPI_LV_DEBUG_OBJECT 342Stores to objects 343.It Li ACPI_LV_INFO 344General information and progress 345.It Li ACPI_LV_ALL_EXCEPTIONS 346All the previous levels 347.It Li ACPI_LV_INIT_NAMES 348.It Li ACPI_LV_PARSE 349.It Li ACPI_LV_LOAD 350.It Li ACPI_LV_DISPATCH 351.It Li ACPI_LV_EXEC 352.It Li ACPI_LV_NAMES 353.It Li ACPI_LV_OPREGION 354.It Li ACPI_LV_BFIELD 355.It Li ACPI_LV_TABLES 356.It Li ACPI_LV_VALUES 357.It Li ACPI_LV_OBJECTS 358.It Li ACPI_LV_RESOURCES 359.It Li ACPI_LV_USER_REQUESTS 360.It Li ACPI_LV_PACKAGE 361.It Li ACPI_LV_VERBOSITY1 362All the previous levels 363.It Li ACPI_LV_ALLOCATIONS 364.It Li ACPI_LV_FUNCTIONS 365.It Li ACPI_LV_OPTIMIZATIONS 366.It Li ACPI_LV_VERBOSITY2 367.It Li ACPI_LV_ALL 368.It Li ACPI_LV_MUTEX 369.It Li ACPI_LV_THREADS 370.It Li ACPI_LV_IO 371.It Li ACPI_LV_INTERRUPTS 372.It Li ACPI_LV_VERBOSITY3 373All the previous levels 374.It Li ACPI_LV_AML_DISASSEMBLE 375.It Li ACPI_LV_VERBOSE_INFO 376.It Li ACPI_LV_FULL_TABLES 377.It Li ACPI_LV_EVENTS 378.It Li ACPI_LV_VERBOSE 379All levels after 380.Qq Li ACPI_LV_VERBOSITY3 381.El 382.Pp 383Selection of the appropriate layer and level values is important 384to avoid massive amounts of debugging output. 385For example, the following configuration is a good way to gather initial 386information. 387It enables debug output for both ACPI-CA and the 388.Nm 389driver, printing basic information about errors, warnings, and progress. 390.Bd -literal -offset indent 391debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS" 392debug.acpi.level="ACPI_LV_ALL_EXCEPTIONS" 393.Ed 394.Pp 395Debugging output by the ACPI CA subsystem is prefixed with the 396module name in lowercase, followed by a source line number. 397Output from the 398.Fx Ns -local 399code follows the same format, but 400the module name is uppercased. 401.Sh OVERRIDING YOUR BIOS BYTECODE 402ACPI interprets bytecode named AML 403(ACPI Machine Language) 404provided by the BIOS vendor as a memory image at boot time. 405Sometimes, the AML code contains a bug that does not appear when parsed 406by the Microsoft implementation. 407.Fx 408provides a way to override it with your own AML code to work around 409or debug such problems. 410Note that all AML in your DSDT and any SSDT tables is overridden. 411.Pp 412In order to load your AML code, you must edit 413.Pa /boot/loader.conf 414and include the following lines. 415.Bd -literal -offset indent 416acpi_dsdt_load="YES" 417acpi_dsdt_name="/boot/acpi_dsdt.aml" # You may change this name. 418.Ed 419.Pp 420In order to prepare your AML code, you will need the 421.Xr acpidump 8 422and 423.Xr iasl 8 424utilities and some ACPI knowledge. 425.Sh COMPATIBILITY 426ACPI is only found and supported on i386/ia32, ia64, and amd64. 427.Sh SEE ALSO 428.Xr kenv 1 , 429.Xr acpi_thermal 4 , 430.Xr device.hints 5 , 431.Xr loader.conf 5 , 432.Xr acpiconf 8 , 433.Xr acpidump 8 , 434.Xr config 8 , 435.Xr iasl 8 436.Rs 437.%A "Compaq Computer Corporation" 438.%A "Intel Corporation" 439.%A "Microsoft Corporation" 440.%A "Phoenix Technologies Ltd." 441.%A "Toshiba Corporation" 442.%D August 25, 2003 443.%T "Advanced Configuration and Power Interface Specification" 444.%O http://acpi.info/spec.htm 445.Re 446.Sh AUTHORS 447.An -nosplit 448The ACPI CA subsystem is developed and maintained by 449Intel Architecture Labs. 450.Pp 451The following people made notable contributions to the ACPI subsystem 452in 453.Fx : 454.An Michael Smith , 455.An Takanori Watanabe Aq takawata@jp.FreeBSD.org , 456.An Mitsuru IWASAKI Aq iwasaki@jp.FreeBSD.org , 457.An Munehiro Matsuda , 458.An Nate Lawson , 459the ACPI-jp mailing list at 460.Aq acpi-jp@jp.FreeBSD.org , 461and many other contributors. 462.Pp 463This manual page was written by 464.An Michael Smith Aq msmith@FreeBSD.org . 465.Sh BUGS 466If the 467.Nm 468driver is loaded as a module when it is already linked as part of the 469kernel, odd things may happen. 470